[Andreas]

This is a FAQ and is being asked over and over and over again

<form action="http://www.yoursite.com/forums/login.php" method="post" onsubmit="md5hash(vb_login_password,vb_login_md5password,vb_login_md5password_utf)">
<script type="text/javascript" src="http://www.yoursite.com/forums/clientscript/vbulletin_md5.js"></script>
Username: <input type="text" name="vb_login_username" size="10" accesskey="u" tabindex="1" value="User Name" onfocus="if (this.value == 'User Name') this.value = '';" /><br />
<label for="cb_cookieuser"><input type="checkbox" name="cookieuser" value="1" tabindex="3" id="cb_cookieuser" accesskey="c" checked="checked" />Remember Me?</label><br />
Password: <input type="password" class="button" name="vb_login_password" size="10" accesskey="p" tabindex="2" />
<input type="submit" class="button" value="Log in" tabindex="4" title="Enter your username and password in the boxes provided to login" accesskey="s" />
<input type="hidden" name="do" value="login" />		
<input type="hidden" name="vb_login_md5password" />
<input type="hidden" name="vb_login_md5password_utf" />
<input type="hidden" name="url" value="http://www.foobar.com" />
</form>

Replace http://www.foobar.com with whatever URL you want to redirect to.