function formvalid(theForm)
{
  if (theForm.amount.value == "")
  {
    alert("Please enter an amount.");
    theForm.amount.focus();
    return (false);
  }
  if (theForm.orderRef.value == "")
  {
    alert("Please enter the \"Order Reference\" number provided in your booking details e-mail.");
    theForm.orderRef.focus();
    return (false);
  }
 return (true);
}