function toggleDT(theObj) {
	var disp = theObj.nextSibling.style.display;
	if (disp=="" || disp=="block") {
		theObj.nextSibling.style.display="none";
		theObj.style.background="url(/images/plus.gif) no-repeat";
		theObj.style.backgroundPosition="left";
	} else {
		theObj.nextSibling.style.display="block";
		theObj.style.background="url(/images/minus.gif) no-repeat";
		theObj.style.backgroundPosition="left";
	}
}

//assign event handler to set of tags in a div.
function setevt(evt,divId,tagname,funcstr) {
	var theDiv=document.getElementById(divId);
	var theTags=theDiv.getElementsByTagName(tagname);
	for (var i=0; i < theTags.length; i++) {
		//theTags[i].setAttribute("onclick",funcstr); <- doesn't work in IE
		eval("theTags[i]." + evt + "=function(){" + funcstr + "}");
		toggleDT(theTags[i]);
	}
}