// JavaScript Document
function check(feedback)
{
  if (feedback.Name.value == "")
  {
    alert("Please enter your name.");

    feedback.Name.focus();

    return (false);

  }

  if (feedback.Telephone.value == "")

  {

    alert("Please enter a contact telephone number.");

    feedback.Telephone.focus();

    return (false);

  }
   if (feedback.Email.value == "")
  {
    alert("Please enter your email address.");

    feedback.Email.focus();

    return (false);

  }
   if (feedback.Enquiry.value == "")
  {
    alert("Please enter your enquiry.");

    feedback.Enquiry.focus();

    return (false);
  }
  return (true);
}
<!-- Begin
function toForm() {
document.feedback.Name.focus();
// Replace Name in the script with the field name of which you want to place the focus.
}
//  End -->