function btnToggle(btn){
	var dispChElmnts = getByClass(document,"mm","img");

	for(i=0;i<dispChElmnts.length;i++){
		
		if(btn.firstChild == dispChElmnts[i]){
			if(dispChElmnts[i].src.search("_on.gif") == -1){
				dispChElmnts[i].src = dispChElmnts[i].src.replace(".gif","_on.gif");
			}
		}else{
			if(dispChElmnts[i].src.search("_on.gif") != -1){
				dispChElmnts[i].src = dispChElmnts[i].src.replace("_on.gif",".gif");
			}
		}

	}
}

function getByClass(parentElmnt,className,tagName){
	var cElmnts = new Array();
	var elmnts = parentElmnt.getElementsByTagName(tagName);
	for(i=0;i<elmnts.length;i++){
		if(elmnts[i].className == className){
			cElmnts.push(elmnts[i]);
		}
	}
	return cElmnts;
}