Form in widget unable to send to post

Hello. Yesterday i had some help to add a form in a widget through this topic
https://help.forumotion.com/t132784-contact-in-any-widget-is-it-possible#892842

The result is this:

but when i try to send the text to the post it doesn't send it. Why?

The code i use is this:

Code:

<div class="formastore"><form enctype="multipart/form-data" onsubmit="return vB_Editor['text_editor'].prepare_submit(0,0)" name="post" method="post" action="/posting.forum">
    <b>Username (Ψευδώνυμο):</b><br /><br />
<input style="width: 17%;" class="posting-subject" onkeypress="if (event.keyCode==13){return false}" maxlength="100" value="" name="subject" type="text"><br /><br />
<b>Πείτε μας τι θέλετε από το Store:</b><br /><br />
 <textarea onselect="storeCaret(this)" tabindex="3" name="message" onkeyup="storeCaret(this)" cols="100" rows="13" onclick="storeCaret(this)"></textarea>
 <input value="0" name="lt" type="hidden"><input value="newtopic" name="mode" type="hidden"><br /><br />
 <input name="f" type="hidden" value="http://informationforumgr.forumgreek.com/f63-forum" <br><input accesskey="s" tabindex="6" value="Aποστολή" name="post" type="submit"><br>
</form></div>