var regex = new RegExp("[a-z0-9._-]{1,}@[a-z0-9.-]{3,}", "gi");

var message0 = "- Please fill in your name.\n";
var message1 = "- Please fill in your e-mail address.\n";

function controles()
{        var message = "";
         if (document.form1.Name.value.length == 0)
                { message += message0;}
         if (document.form1.Email.value.search(regex) == -1)
                { message += message1;}
        
  if (message.length > 0)
     { window.alert("Your message has not been sent. \n\n" + message);}
  else
     { document.form1.submit();}
}