function checklogin( input ) {
	if( !input.email.value ) {
        alert(" Please enter an email address. ");
        input.email.focus();
        input.email.select();
        return false;
      }
	// checks that the email format is valid (xxx@xxx.xxx)  
	else {
      var re_mail = /^([a-zA-Z0-9_\.\-])+\@(([a-zA-Z0-9\-])+\.)+([a-zA-Z])+$/;
      if( !re_mail.test( input.email.value ) ) {
        alert(" Please enter a valid email address. ");
        input.email.focus();
        input.email.select();
        return false;
      }
    } 
	if( !input.password.value ) {
        alert(" Please enter a password. ");
        input.password.focus();
        input.password.select();
        return false;
      }
return true;
}