function images_swap(id,post)
{
	var i;
    i=by_id(id);
    var re = new RegExp(post,"ig");
	if (i)
	{
	    if (i.src.search(re)==-1)
	    {
	    	i.src=i.src.substr(0,i.src.length-4)+post+i.src.substr(i.src.length-4);
		}
		else
		{
			i.src=i.src.replace(re,"");
		}
	}
	//alert(i.src);
}
sub1on = new Image();
sub1on.src = "images/staff_on.gif";
sub2on = new Image();
sub2on.src = "images/hours_and_location_on.gif";
sub3on = new Image();
sub3on.src = "images/contact_us_on.gif";
sub4on = new Image();
sub4on.src = "images/home_on.gif";