function validate() {

 var name = document.getElementById('name').value;
 var email = document.getElementById('email').value;
 var comment = document.getElementById('comment').value;
 
 if ( (name == '') || (email == '') || (comment == '') ) { 
   alert('Required Field Missing, Please check and try again.');
   return false;
 }
 
 var stremail = email;
 var emailchar = /^([\w-]+(?:\.[\w-]+)*)@((?:[\w-]+\.)*\w[\w-]{0,66})\.([a-z]{2,6}(?:\.[a-z]{2})?)$/i;
 if (!(emailchar.test(stremail))) {
   alert('Please give a valied email addrress.');
   return false;
 }
 document.form.submit();
}