function validate_fields(Form)
{

  if (Form.name.value == "")
  {
    alert("Please enter your Name in the \"Name\" field.");
    Form.name.focus();
    return (false);
  }

  if (Form.name.value.length < 3)
  {
    alert("Please enter your Name in the \"Name\" field.");
    Form.name.focus();
    return (false);
  }

  if (Form.email.value == "")
  {
    alert("Please enter a valid e-mail address in the \"E-mail\" field.");
    Form.email.focus();
    return (false);
  }

  if (Form.email.value.length < 8)
  {
    alert("Please enter a valid e-mail address in the \"E-mail\" field.");
    Form.email.focus();
    return (false);
  }

  var checkOK = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789-.-@_";
  var checkStr = Form.email.value;
  var allValid = true;
  for (i = 0;  i < checkStr.length;  i++)
  {
    ch = checkStr.charAt(i);
    for (j = 0;  j < checkOK.length;  j++)
      if (ch == checkOK.charAt(j))
        break;
    if (j == checkOK.length)
    {
      allValid = false;
      break;
    }
  }
  if (!allValid)
  {
    alert("Please enter a VALID e-mail address in the \"E-mail\" field.");
    Form.email.focus();
    return (false);
  }

  if (Form.telephone.value == "")
  {
    alert("Please enter your Telephone No. in the \"Telephone No.\" field.");
    Form.telephone.focus();
    return (false);
  }

  if (Form.telephone.value.length < 11)
  {
    alert("Please include STD code in the \"Telephone No.\" field.");
    Form.telephone.focus();
    return (false);
  }

  if (Form.telephone.value.length > 18)
  {
    alert("Please enter a valid length Telephone number in the \"Telephone No.\" field.");
    Form.telephone.focus();
    return (false);
  }

  var checkOK = "0123456789-()+. \t\r\n\f";
  var checkStr = Form.telephone.value;
  var allValid = true;
  for (i = 0;  i < checkStr.length;  i++)
  {
    ch = checkStr.charAt(i);
    for (j = 0;  j < checkOK.length;  j++)
      if (ch == checkOK.charAt(j))
        break;
    if (j == checkOK.length)
    {
      allValid = false;
      break;
    }
  }
  if (!allValid)
  {
    alert("Please enter only digits in the \"Telephone No.\" field.");
    Form.telephone.focus();
    return (false);
  }
  return (true);
}