Creating Collapsible Sections

This is a nice space saver, especially for "crowded" forms. Would be even nicer if ms provided this out of the box. You can set the initial state of the section in the onload event.

function OnCrmPageLoad() {    
   /* false - collapsed, true - expanded */
   //First Tab, Second Section, Expanded
   ConvertSection(0,1,true);
   //Second Tab, Second Section, Collapsed
   ConvertSection(1,1,false); 
}

function ConvertSection( tabIndex , sectionIndex , state ) {
   var sec = document.getElementById( "tab" + tabIndex );
   var td = sec.childNodes[0].rows[ sectionIndex ].cells[0].childNodes[0].rows[0].cells[0];
   var secHTML = td.innerHTML;
   state = (typeof(state) == "undefined")? false:!state;
   var src = (state == false)? "/_imgs/tree/dashPlus.gif":"/_imgs/tree/dashMinus.gif";
   td.innerHTML = "<NOBR style='VERTICAL-ALIGN: middle;cursor:hand' onclick='excoSection(this)'><IMG src='" + src + "' align='middle' /> " + td.innerHTML + "</NOBR>";
   td.childNodes[0].childNodes[0].state = state;
   excoSection(td.childNodes[0]); 
}

/* Toggle SectionState */ 
function excoSection( sec ) {
   sec = sec.childNodes[0];
   sec.state = !sec.state;
   sec.src = (sec.state)? "/_imgs/tree/dashMinus.gif":"/_imgs/tree/dashPlus.gif";
   var display = (sec.state)? "inline" :"none";
   var tblsec = sec.parentElement.parentElement.parentElement.parentElement;
   for( var i =1 ; i < tblsec.rows.length ; i++ )
      tblsec.rows[i].style.display = display;
}
//Expose the toggling function at the window level
this.excoSection = excoSection;

OnCrmPageLoad();