var disp = new Number(1);
function y_display(obj){
	var item = new Array("y_gry","y_blue","y_sky","y_grn","y_ylw","y_org","y_red");
	if(obj == 0){
		for(i=1;i<7;i++){
			document.all(item[i]).style.display="";
		}
	}
	else{
		if(disp == 0){
			for(i=1;i<7;i++){
				document.all(item[i]).style.display="none";
			}
		}
		else{
			document.all(item[disp]).style.display="none";
		}
		document.all(item[obj]).style.display="";
	}
	disp = obj;
}