// function:  verify ALL input fields are populated
function checkFormFields() {
   var _f = document.rrgs;

   // iterate thru all form elements [including hidden, submit, and reset]
   for (var i = 0; i < _f.elements.length; i++) {
      // check to avoid requiring values for Submit/Reset fields
      if (_f.elements[i].name != '')
         if (_f.elements[i].value == '') {
            alert("Please complete the " + _f.elements[i].name + " field.");
            return false;
            }
   }

   return true;
}