function IsEmail (s)
{
        if (s.length > 100)
        {
                //window.alert("Email地址长度不能超过100位!");
                return false;
        }

         var regu = "^(([0-9a-zA-Z]+)|([0-9a-zA-Z]+[_.0-9a-zA-Z-]*[0-9a-zA-Z]+))@([a-zA-Z0-9-]+[.])+([a-zA-Z]{2}|net|com|gov|mil|org|edu|int)$"
         var re = new RegExp(regu);
         if (s.search(re) != -1) {
               return true;
         } else {
               //window.alert ("请输入有效合法的E-mail地址 ！")
               return false;
         }
}
function submitcheck(){
	 var Email;
	 Email = document.getElementById("Email")
	 if ((Email.value=="")|| !IsEmail(Email.value))
      {
        alert("Please enter e_mail!");
        Email.focus();
		return false;
      }
      return true;
	   }