function isValid()
{
	var formIsValid = true;
	$(".required").each( function(i, f)
	{
		var fieldIsValid = true;
		var field = $(f);
		if( field.val() == "" )
		{
			fieldIsValid = false;
		}

		switch(field.attr("id"))
		{
			case "email_field":
			{
				var pattern=/^([a-zA-Z0-9_.-])+@([a-zA-Z0-9_.-])+\.([a-zA-Z])+([a-zA-Z])+/;
				if(!pattern.test( field.val() ))
				{
					fieldIsValid = false;
				}
				break;
			}

		}

		if(!fieldIsValid)
		{
			field.css("border-color", "#f99");
			field.css("background-color", "#fff0f0");
		}
		else
		{
			field.css("border-color", "#999");
			field.css("background-color", "#f5f5f5");
		}

		formIsValid = formIsValid && fieldIsValid;
	});

	if(!formIsValid)
	{
		alert("One or more of the fields you filled in appear to be invalid. Please correct the fields marked in red");
		return false;
	}

	return true;
}