Vd. VBScript

if InStr((request.form(\"mail\"),\"@\") then
  Response.write \"ok mail\"
end if

fandt selv ud af det ;-)

<Script language=\"VBScript\">
<!--
Sub Form_OnSubmit

If InStr(form.mail.value, \"@\") < 1 OR InStr(form.mail.value, \".\") < 1 Then
msgbox \"Wrong E-mail address!\"
Else
msgbox \"OK! E-mail address!\"
End If

End Sub
-->
</script>

=> soenderup

det skulle være i normal VBScript -ikke i ASP! :-(