function mailCheck(mailInput){ 
 	var ok;
	ok = true;
	var re_mail = /^([a-zA-Z])+$/;
	
	if (mailInput.value.length > 0){      	
    x = mailInput.value.split("@");
		if (x.length < 2) {ok = false;}
		else 
    {
		  y = x[1].split(".");
			if (ok && y.length < 2) {ok = false;}
			else 
      {
			  for (i=0; i<y.length; i++) 
        {
    			if (y[i].length < 1) {ok = false;}
    			last = y[i];
  			}
				if(last.length < 2) {ok = false;}        
				if (!re_mail.test(last)) 
				{
				  ok = false;
				}
			 }
      }
  }
  else
    ok = false;
  return ok;
}