function validate_required(field,alerttxt)
{
  with (field)
  {
    if (value==null||value=="")
      {alert(alerttxt);return false}
    else {return true}
  }
}

function validate_email(field,alerttxt)
{
  with (field)
  {
    apos=value.indexOf("@")
    dotpos=value.lastIndexOf(".")
    if (apos<1||dotpos-apos<2)
      {alert(alerttxt);return false}
    else {return true}
  }
}

function validate_form(thisform)
{
  with (thisform)
  {
    if (validate_required(first,"Please specify your name!")==false)
      {first.focus();return false}
    if (validate_required(phone,"Please enter your phone number!")==false)
      {phone.focus();return false}
    if (validate_required(email,"Please enter your email address!")==false)
      {email.focus();return false}
    if (validate_email(email,"Not a valid e-mail address!")==false)
      {email.focus();return false}

  }
}