[kh99]

You could try something like this:

<form name="input" action="vb418/newthread.php?do=newthread" method="post">
Judul: <input type="text" name="subject" />
isi: <input type="text" name="message" />
forum: <input type="text" name="forumid" />
<input type="hidden" name="do" value="postthread"/>
<input type="hidden" name="preview" value="1"/>
<input type="hidden" name="securitytoken" value="<?php echo($vbulletin->userinfo['securitytoken']); ?>" />
<input type="submit" value="Submit" />
</form>