You have the option of doing a lot of things
<input type="hidden" name="s" value="$session[sessionhash]">
<input type="hidden" name="action" value="postreply">
<input type="hidden" name="threadid" value="$threadid">
<input type="hidden" name="title" value="">
<input type="hidden" name="iconid" value="0">
<input type="hidden" name="parseurl" value="yes">
<input type="hidden" name="email" value="">
<input type="hidden" name="disablesmilies" value="">
<input type="hidden" name="closethread" value="">
<input type="hidden" name="hiddenreply" value="">
<input type="hidden" name="signature" value="yes">
<input type="hidden" name="rating" value="0">
just make this line
<input type="hidden" name="signature" value="no">
turn the value off and on
It's located in the quick reply template