bir dosyayı include etmek yerine loginform' u entegre etmen daha kolay ve sağlıklı olacaktır
Jomlada Uygun Bir yere Bu Kodları Siteadi.com kısımlarını değiştirerek ekleyin

bu haliyle işinize görecektir

nuke + mybb bu şekilde kullanıyorum ben

<form action="http://www.siteadi.com/forum/login.php" method="post" target="_blank" style="display: inline" onsubmit="md5hash(vb_login_password,vb_login_md5pa ssword,vb_ login_md5password_utf)">
<input type="hidden" value="login" name="do">
<input type="hidden" value="1" name="forceredirect">
<input type="hidden" value="http://www.siteadi.com/forum/index.php" name="url">
<input type="hidden" name="vb_login_md5password">
<input type="hidden" name="vb_login_md5password_utf">
<input type="hidden" name="s">
<table cellSpacing="3" cellPadding="0" align="center" border="0" width="107">
<tr>
<td style="font-size: 11px; font-style: normal; font-variant: normal; font-weight: normal; font-family: verdana, geneva, lucida, 'lucida grande', arial, helvetica, sans-serif" width="164">
<font color="#FFFFFF">Kullanici Adi:</font><br>
<input class="bginput" accessKey="u" tabIndex="1" size="12" name="vb_login_username"></td>
</tr>
<tr>
<td style="font-size: 11px; font-style: normal; font-variant: normal; font-weight: normal; font-family: verdana, geneva, lucida, 'lucida grande', arial, helvetica, sans-serif" width="164">
<font color="#FFFFFF">Sifre:</font><br>
<input class="bginput" accessKey="p" tabIndex="1" type="password" size="12" value name="vb_login_password"></td>
</tr>
<tr>
<td style="font-size: 11px; font-style: normal; font-variant: normal; font-weight: normal; font-family: verdana, geneva, lucida, 'lucida grande', arial, helvetica, sans-serif" width="164">
<p align="justify"><span style="FLOAT: right">
<a href="http://www.siteadi.com/forum/login.php?do=lostpw" style="color: #000020; text-decoration: none">
<font color="#FFFFFF">Sifremi unuttum</font></a></span>
<label for="cb_cookieuser" style="cursor: default">
<input id="cb_cookieuser" tabIndex="1" type="checkbox" CHECKED value="1" name="cookieuser"><font color="#FFFFFF">Beni
Hatirla</font>
<div align="center">
<a href="http://www.siteadi.com/forum/register.php"><b>
<font color="#FFFFFF">Kayit Ol</font></b><font color="#FFFFFF"> </font>
</a>
</div>
</label> </td>
</tr>
<tr>
<td align="right" style="font-size: 11px; font-style: normal; font-variant: normal; font-weight: normal; font-family: verdana, geneva, lucida, 'lucida grande', arial, helvetica, sans-serif" width="164">
<input class="button" accessKey="s" tabIndex="1" type="submit" value="Baglan" style="float: right; border: 1px solid #3E5C92; padding-left: 4; padding-right: 4; padding-top: 1; padding-bottom: 1">
</td>
</tr>
</table>
</form>

Dip not Aradaki tabloyu kaldırabilir yada görsellik kazandırabilirsin