Ok, try this..
In the showthread template find and delete this code (you just added it):
Code:
<script language="Javascript" src="vbcode.js"></script>
<script language="Javascript" src="vbcode_language.js"></script>
Find:
Code:
<tr>
<td bgcolor="{tableheadbgcolor}" colspan="2">
<normalfont color="{tableheadtextcolor}"><b>Post Reply:</b></normalfont>
</td>
</tr>
Below it add:
Code:
<form enctype="multipart/form-data" action="newreply.php" name="quickreply" method="post" onSubmit="return validate(this)">
<script language="Javascript" src="vbcode.js"></script>
<script language="Javascript" src="vbcode_language.js"></script>
A few lines below that find:
Code:
<form enctype="multipart/form-data" action="newreply.php" name="quickreply" method="post" onSubmit="return validate(this)">
..and delete it.
That should do it.