$(document).ready(function(){ 
				$("#contact_button").click(function(){ //click on #contact-button
				$("#hidden_bg").slideToggle("slow", contact);  //runs "slideToggle" on #hidden_bg
				return false;
				});
				});
				function contact()
				{
				 //change between classes
				
				$("#contact_button").toggleClass("contact_active");
				$("#contact_button").toggleClass("contact");
				
        }