var head="display:''";

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 = '';
		}
		else {
			nested.style.display = "none";			
		}
	}
}

document.onclick = change;