function validateForm ( form ) {
   for ( var e = 0; e < form.elements.length; e ++ ) {
      var el = form.elements [ e ];
      if ( el.type == 'text' || el.type == 'textarea' || 
         el.type == 'password' || el.type == 'file' ) {
         // check text fields
         if ( el.value == '' || el.value == 'Departure Date'|| el.value == 'Destination' || el.value == 'Return Date' || el.value == 'Forename' || el.value == 'Surname' || el.value == 'Phone' || el.value == 'Email') {
            alert ( 'Please fill out the ' + el.name + ' field' );
            el.focus ( );
            return false;
         }
		}
	}
   return true;
}