http://eyedmax.com/2008/05/28/fixed-boxover-js-library/
http://opatia.com/js/BoxOverParameters.htm

Dragbox-Patch: http://keul.it/develop/javascript/

<script type="text/javascript">
//<![CDATA[
/* --- BoxOver ---
/* --- v 2.1 17th June 2006
By Oliver Bryant with help of Matthew Tagg
http://boxover.swazz.org */

if (typeof document.attachEvent!='undefined') {
   window.attachEvent('onload',init);
   document.attachEvent('onmousemove',moveMouse);
   document.attachEvent('onclick',checkMove); }
else {
   window.addEventListener('load',init,false);
   document.addEventListener('mousemove',moveMouse,false);
   document.addEventListener('click',checkMove,false);
}

var oDv=document.createElement("div");
var dvHdr=document.createElement("div");
var dvBdy=document.createElement("div");
var windowlock,boxMove,fixposx,fixposy,lockX,lockY,fixx,fixy,ox,oy,boxLeft,boxRight,boxTop,boxBottom,evt,mouseX,mouseY,boxOpen,totalScrollTop,totalScrollLeft;
boxOpen=false;
ox=10;
oy=10;
function init() {
        oDv.appendChild(dvHdr);
        oDv.appendChild(dvBdy);
        oDv.style.position="absolute";
        oDv.style.visibility='hidden';
        document.body.appendChild(oDv);
}

function defHdrStyle() {
        dvHdr.innerHTML='&nbsp;&nbsp;'+dvHdr.innerHTML;
        dvHdr.style.fontWeight='bold';
        dvHdr.style.width='150px';
        dvHdr.style.fontFamily='arial';
        dvHdr.style.border='1px solid #A5CFE9';
        dvHdr.style.padding='3';
        dvHdr.style.fontSize='11';
        dvHdr.style.color='#4B7A98';
        dvHdr.style.background='#D5EBF9';
        dvHdr.style.filter='alpha(opacity=85)'; // IE
        dvHdr.style.opacity='0.85'; // FF
}

function defBdyStyle() {
        dvBdy.style.borderBottom='1px solid #A5CFE9';
        dvBdy.style.borderLeft='1px solid #A5CFE9';
        dvBdy.style.borderRight='1px solid #A5CFE9';
        dvBdy.style.width='150px';
        dvBdy.style.fontFamily='arial';
        dvBdy.style.fontSize='11';
        dvBdy.style.padding='3';
        dvBdy.style.color='#1B4966';
        dvBdy.style.background='#FFFFFF';
        dvBdy.style.filter='alpha(opacity=85)'; // IE
        dvBdy.style.opacity='0.85'; // FF
}

function checkElemBO(txt) {
if (!txt || typeof(txt) != 'string') return false;
if ((txt.indexOf('header')>-1)&&(txt.indexOf('body')>-1)&&(txt.indexOf('[')>-1)&&(txt.indexOf('[')>-1))
   return true;
else
   return false;
}

function scanBO(curNode) {
          if (checkElemBO(curNode.title)) {
         curNode.boHDR=getParam('header',curNode.title);
         curNode.boBDY=getParam('body',curNode.title);
                        curNode.boCSSBDY=getParam('cssbody',curNode.title);                     
                        curNode.boCSSHDR=getParam('cssheader',curNode.title);
                        curNode.IEbugfix=(getParam('hideselects',curNode.title)=='on')?true:false;
                        curNode.fixX=parseInt(getParam('fixedrelx',curNode.title));
                        curNode.fixY=parseInt(getParam('fixedrely',curNode.title));
                        curNode.absX=parseInt(getParam('fixedabsx',curNode.title));
                        curNode.absY=parseInt(getParam('fixedabsy',curNode.title));
                        curNode.offY=(getParam('offsety',curNode.title)!='')?parseInt(getParam('offsety',curNode.title)):10;
                        curNode.offX=(getParam('offsetx',curNode.title)!='')?parseInt(getParam('offsetx',curNode.title)):10;
                        curNode.fade=(getParam('fade',curNode.title)=='on')?true:false;
                        curNode.fadespeed=(getParam('fadespeed',curNode.title)!='')?getParam('fadespeed',curNode.title):0.04;
                        curNode.delay=(getParam('delay',curNode.title)!='')?parseInt(getParam('delay',curNode.title)):0;
                        if (getParam('requireclick',curNode.title)=='on') {
                                curNode.requireclick=true;
                                document.all?curNode.attachEvent('onclick',showHideBox):curNode.addEventListener('click',showHideBox,false);
                                document.all?curNode.attachEvent('onmouseover',hideBox):curNode.addEventListener('mouseover',hideBox,false);
                        }
                        else {// Note : if requireclick is on the stop clicks are ignored                       
                        if (getParam('doubleclickstop',curNode.title)!='off') {
                                document.all?curNode.attachEvent('ondblclick',pauseBox):curNode.addEventListener('dblclick',pauseBox,false);
                        }       
                        if (getParam('singleclickstop',curNode.title)=='on') {
                                document.all?curNode.attachEvent('onclick',pauseBox):curNode.addEventListener('click',pauseBox,false);
                        }
                }
                        curNode.windowLock=getParam('windowlock',curNode.title).toLowerCase()=='off'?false:true;
                        curNode.title='';
                        curNode.hasbox=1;
           }
           else
              curNode.hasbox=2;   
}

function getParam(param,list) {
        var reg = new RegExp('([^a-zA-Z]' + param + '|^' + param + ')\\s*=\\s*\\[\\s*(((\\[\\[)|(\\]\\])|([^\\]\\[]))*)\\s*\\]');
        var res = reg.exec(list);
        var returnvar;
        if(res)
                return res[2].replace('[[','[').replace(']]',']');
        else
                return '';
}

function Left(elem){    
        var x=0;
        if (elem.calcLeft)
                return elem.calcLeft;
        var oElem=elem;
        while(elem){
                 if ((elem.currentStyle)&& (!isNaN(parseInt(elem.currentStyle.borderLeftWidth)))&&(x!=0))
                        x+=parseInt(elem.currentStyle.borderLeftWidth);
                 x+=elem.offsetLeft;
                 elem=elem.offsetParent;
          }
        oElem.calcLeft=x;
        return x;
        }

function Top(elem){
         var x=0;
         if (elem.calcTop)
                return elem.calcTop;
         var oElem=elem;
         while(elem){           
                 if ((elem.currentStyle)&& (!isNaN(parseInt(elem.currentStyle.borderTopWidth)))&&(x!=0))
                        x+=parseInt(elem.currentStyle.borderTopWidth);
                 x+=elem.offsetTop;
                 elem=elem.offsetParent;
         }
         oElem.calcTop=x;
         return x;
}

var ah,ab;
function applyStyles() {
        if(ab)
                oDv.removeChild(dvBdy);
        if (ah)
                oDv.removeChild(dvHdr);
        dvHdr=document.createElement("div");
        dvBdy=document.createElement("div");
        CBE.boCSSBDY?dvBdy.className=CBE.boCSSBDY:defBdyStyle();
        CBE.boCSSHDR?dvHdr.className=CBE.boCSSHDR:defHdrStyle();
        dvHdr.innerHTML=CBE.boHDR;
        dvBdy.innerHTML=CBE.boBDY;
        ah=false;
        ab=false;
        if (CBE.boHDR!='') {            
                oDv.appendChild(dvHdr);
                ah=true;
        }       
        if (CBE.boBDY!=''){
                oDv.appendChild(dvBdy);
                ab=true;
        }       
}

var CSE,iterElem,LSE,CBE,LBE, totalScrollLeft, totalScrollTop, width, height ;
var ini=false;

// Customised function for inner window dimension
function SHW() {
   if (document.body && (document.body.clientWidth !=0)) {
      width=document.body.clientWidth;
      height=document.body.clientHeight;
   }
   if (document.documentElement && (document.documentElement.clientWidth!=0) && (document.body.clientWidth + 20 >= document.documentElement.clientWidth)) {
      width=document.documentElement.clientWidth;   
      height=document.documentElement.clientHeight;   
   }   
   return [width,height];
}


var ID=null;
function moveMouse(e) {
   //boxMove=true;
        e?evt=e:evt=event;
        
        CSE=evt.target?evt.target:evt.srcElement;
        
        if (!CSE.hasbox) {
           // Note we need to scan up DOM here, some elements like TR don't get triggered as srcElement
           iElem=CSE;
           while ((iElem.parentNode) && (!iElem.hasbox)) {
              scanBO(iElem);
              iElem=iElem.parentNode;
           }       
        }
        
        if ((CSE!=LSE)&&(!isChild(CSE,dvHdr))&&(!isChild(CSE,dvBdy))){          
           if (!CSE.boxItem) {
                        iterElem=CSE;
                        while ((iterElem.hasbox==2)&&(iterElem.parentNode))
                                        iterElem=iterElem.parentNode;
                        CSE.boxItem=iterElem;
                        }
                iterElem=CSE.boxItem;
                if (CSE.boxItem&&(CSE.boxItem.hasbox==1))  {
                        LBE=CBE;
                        CBE=iterElem;
                        if (CBE!=LBE) {
                                applyStyles();
                                if (!CBE.requireclick)
                                        if (CBE.fade) {
                                                if (ID!=null)
                                                        clearTimeout(ID);
                                                ID=setTimeout("fadeIn("+CBE.fadespeed+")",CBE.delay);
                                        }
                                        else {
                                                if (ID!=null)
                                                        clearTimeout(ID);
                                                COL=1;
                                                ID=setTimeout("oDv.style.visibility='visible';ID=null;",CBE.delay);                                             
                                        }
                                if (CBE.IEbugfix) {hideSelects();}
                                fixposx=!isNaN(CBE.fixX)?Left(CBE)+CBE.fixX:CBE.absX;
                                fixposy=!isNaN(CBE.fixY)?Top(CBE)+CBE.fixY:CBE.absY;                    
                                lockX=0;
                                lockY=0;
                                boxMove=true;
                                ox=CBE.offX?CBE.offX:10;
                                oy=CBE.offY?CBE.offY:10;
                        }
                }
                else if (!isChild(CSE,dvHdr) && !isChild(CSE,dvBdy) && (boxMove))       {
                        // The conditional here fixes flickering between tables cells.
                        if ((!isChild(CBE,CSE)) || (CSE.tagName!='TABLE')) {                    
                        CBE=null;
                        if (ID!=null)
                                        clearTimeout(ID);
                        fadeOut();
                        showSelects();
                        }
                }
                LSE=CSE;
        }
        else if (((isChild(CSE,dvHdr) || isChild(CSE,dvBdy))&&(boxMove))) {
                totalScrollLeft=0;
                totalScrollTop=0;
                
                iterElem=CSE;
                while(iterElem) {
                        if(!isNaN(parseInt(iterElem.scrollTop)))
                                totalScrollTop+=parseInt(iterElem.scrollTop);
                        if(!isNaN(parseInt(iterElem.scrollLeft)))
                                totalScrollLeft+=parseInt(iterElem.scrollLeft);
                        iterElem=iterElem.parentNode;                   
                }
                if (CBE!=null) {
                        boxLeft=Left(CBE)-totalScrollLeft;
                        boxRight=parseInt(Left(CBE)+CBE.offsetWidth)-totalScrollLeft;
                        boxTop=Top(CBE)-totalScrollTop;
                        boxBottom=parseInt(Top(CBE)+CBE.offsetHeight)-totalScrollTop;
                        doCheck();
                }
        }
        
        if (boxMove&&CBE) {
                // This added to alleviate bug in IE6 w.r.t DOCTYPE
                bodyScrollTop=document.documentElement&&document.documentElement.scrollTop?document.documentElement.scrollTop:document.body.scrollTop;
                bodyScrollLet=document.documentElement&&document.documentElement.scrollLeft?document.documentElement.scrollLeft:document.body.scrollLeft;
                mouseX=evt.pageX?evt.pageX-bodyScrollLet:evt.clientX-document.body.clientLeft;
                mouseY=evt.pageY?evt.pageY-bodyScrollTop:evt.clientY-document.body.clientTop;
                if ((CBE)&&(CBE.windowLock)) {
                        mouseY < -oy?lockY=-mouseY-oy:lockY=0;
                        mouseX < -ox?lockX=-mouseX-ox:lockX=0;
                        mouseY > (SHW()[1]-oDv.offsetHeight-oy)?lockY=-mouseY+SHW()[1]-oDv.offsetHeight-oy:lockY=lockY;
                        mouseX > (SHW()[0]-dvBdy.offsetWidth-ox)?lockX=-mouseX-ox+SHW()[0]-dvBdy.offsetWidth:lockX=lockX;                       
                }
                oDv.style.left=((fixposx)||(fixposx==0))?fixposx:bodyScrollLet+mouseX+ox+lockX+"px";
                oDv.style.top=((fixposy)||(fixposy==0))?fixposy:bodyScrollTop+mouseY+oy+lockY+"px";             
                
        }
}

function doCheck() {    
        if (   (mouseX < boxLeft)    ||     (mouseX >boxRight)     || (mouseY < boxTop) || (mouseY > boxBottom)) {
                if (!CBE.requireclick)
                        fadeOut();
                if (CBE.IEbugfix) {showSelects();}
                CBE=null;
        }
}

function pauseBox(e) {
   e?evt=e:evt=event;
        boxMove=false;
        evt.cancelBubble=true;
}

function showHideBox(e) {
        oDv.style.visibility=(oDv.style.visibility!='visible')?'visible':'hidden';
}

function hideBox(e) {
        oDv.style.visibility='hidden';
}

var COL=0;
var stopfade=false;
function fadeIn(fs) {
                ID=null;
                COL=0;
                oDv.style.visibility='visible';
                fadeIn2(fs);
}

function fadeIn2(fs) {
                COL=COL+fs;
                COL=(COL>1)?1:COL;
                oDv.style.filter='alpha(opacity='+parseInt(100*COL)+')';
                oDv.style.opacity=COL;
                if (COL<1)
                 setTimeout("fadeIn2("+fs+")",20);              
}


function fadeOut() {
        oDv.style.visibility='hidden';
        
}

function isChild(s,d) {
        while(s) {
                if (s==d)
                        return true;
                s=s.parentNode;
        }
        return false;
}

var cSrc;
function checkMove(e) {
        e?evt=e:evt=event;
        cSrc=evt.target?evt.target:evt.srcElement;
        if ((!boxMove)&&(!isChild(cSrc,oDv))) {
                fadeOut();
                if (CBE&&CBE.IEbugfix) {showSelects();}
                boxMove=true;
                CBE=null;
        }
}

function showSelects(){
   var elements = document.getElementsByTagName("select");
   for (i=0;i< elements.length;i++){
      elements[i].style.visibility='visible';
   }
}

function hideSelects(){
   var elements = document.getElementsByTagName("select");
   for (i=0;i< elements.length;i++){
   elements[i].style.visibility='hidden';
   }
}
//]]>
</script>