var head="display:''";
img1=new Image();
img1.src="fold.gif";
img2=new Image();
img2.src="open.gif";

function change(){
if(!document.all)
return;
if (event.srcElement.id=="foldheader") {
var srcIndex = event.srcElement.sourceIndex;
var nested = document.all[srcIndex+1];
if (nested.style.display=="none") {
nested.style.display='';
event.srcElement.style.listStyleImage="url(open.gif)";
}
else {
nested.style.display="none";
event.srcElement.style.listStyleImage="url(fold.gif)";
}
}
}

document.onclick=change;