function rollOver(node) {
		var fileName=node.src;
		if (fileName.indexOf('(over)')==-1) {
			x=fileName.length-1;
			while ((x>0) && (fileName.charAt(x)!='.')) x--;
			fileName=fileName.substr(0,x)+'(over)'+fileName.substr(x);
			node.src=fileName;
		}
	}
	
	function rollOut(node) {
		var fileName=node.src, p=fileName.indexOf('(over)');
		if (p!=-1) {
			fileName=fileName.substr(0,p)+fileName.substr(p+6);
			node.src=fileName;
		}
	}