function isValidEmail(str) {                        
   return (str.indexOf(".") > 2) && (str.indexOf("@") > 0);
}

function checkInputContact()
{
	if (document.getElementById("val_name").value=="")
	{
		alert("Input your name");
		return false;
	}
	if (document.getElementById("val_email").value=="")
	{
		alert("Input your email");
		return false;
	}
	
	if (!isValidEmail(document.getElementById("val_email").value))
	{
		alert("is not valid email");
		return false;
	}
	
	if (document.getElementById("val_subject").value=="")
	{
		alert("Input your subject");
		return false;
	}
	if (document.getElementById("val_question").value=="")
	{
		alert("Input your question");
		return false;
	}
	
}