function adHover(isHover){
	if(isHover){
		var normalURL = $("#normal_ad").attr("src");
		var hoverURL = $("#hidden_ad").attr("src");
		$("#normal_ad").attr("src", hoverURL);
		$("#hidden_ad").attr("src", normalURL);
	}
	else if(!isHover){
		var normalURL = $("#hidden_ad").attr("src");
		var hoverURL = $("#normal_ad").attr("src");
		$("#normal_ad").attr("src", normalURL);
		$("#hidden_ad").attr("src", hoverURL);
	}
}

function signupHover(isHover){
	var $image = $(".signup_panel a img");
	
	if(isHover){
		$image.attr("src", "images/signup_panel_hover.gif");
	}
	else if(!isHover){
		$image.attr("src", "images/signup_panel.gif");
	}
}