function toggleAbouts() {
	
	<!-- Array of all layers to be shut off before the target gets turned on  //-->
	
	
	var ids=new Array("main","what_a","what_b","history_a","history_b","history_c","jimmy_a","jimmy_b","jimmy_c","jimmy_d");
	<!-- loop to hie exiting visible layers  	//-->
	for(var i = 0; i < ids.length; i++) {
		var id = ids[i];
			if(document.getElementById(id).style.visibility == "visible"){ 
			document.getElementById(id).style.visibility = "hidden";
			}
	} 

	<!-- Variable to be receive by onClick , target layer to turn on //-->
	var args = arguments;
	<!--  Loop to turn on the target layer  //-->
	for(var i = 0; i < args.length; i++) {
		var id2 = args[i];
			if(document.getElementById(id2).style.visibility == "hidden"){ 
			document.getElementById(id2).style.visibility = "visible";
			}
			else{
			document.getElementById(id2).style.visibility = "hidden";
			}
	}
	
}