// Validation for the Contact page

function verify(f) {
  
  isValid = true;
  checkBoxSelected = false;
  errMsg = "";
  
  // Determine if a contact person is provided
  if (isNull(f.contact_person.value)) {
    isValid = false;
    errMsg = errMsg + "  - A contact person.\n";
  }
  
  // Determine if either a contact telephone or an email address 
  // is provided
  if (isNull(f.contact_telephone.value) && isNull(f.contact_email.value)) {
    isValid = false;
    errMsg = errMsg + "  - Either a contact telephone or an email address.\n";
  }
  
  // Determine if any of the request types (checkboxes) have been
  // selected
  for (i = 0; i < f.request_type.length; i++) {
    if (f.request_type[i].checked) {
      checkBoxSelected = true;
    }
  }
  
  if (!checkBoxSelected) {
    isValid = false;
    errMsg = errMsg + "  - At least one request type.\n";
  }
  
  // Finally determine if the form is valid for submission
  if (isValid) {
    return true;
  } else {
    alert("Please provide the following details:\n" + errMsg);
    return false;
  }
}

function isNull(val) {
  return (val == null || val == '');
}