Insert Text to a field, from a popup window

Hi. I am trying to make smileys to a guestbook, but they are a lot of smileys, so I create a popup window with all the smileys, but I dont know how to insert the text to the original field, from the popup window

I am using this script:

<script language="JavaScript" type="text/JavaScript">
<!--
function InsertarSmile(e, smile)
{
e.value += smile;
e.focus();
}
//-->
</script>

The Original Form Name is: EnviarMensaje
The Field Name is: Mensaje

The URL IS:

<a href="javascript:InsertarSmile(document.EnviarMensaje.Me nsaje, '[] ')"><imagen></a>


Is that possible????


Regards,
Carlos F. Rebolledo

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