[kh99]

Sorry about the extra bracket, I fixed it above.

The form for the existing login/password field in the navbar looks like this:

<script type="text/javascript" src="clientscript/vbulletin_md5.js?v=415"></script>
<form id="navbar_loginform" action="login.php?do=login" method="post" onsubmit="md5hash(vb_login_password, vb_login_md5password, vb_login_md5password_utf, 0)">
	<fieldset id="logindetails" class="logindetails">
		<div>
			<div>
		<input type="text" class="textbox default-value" name="vb_login_username" id="navbar_username" size="10" accesskey="u" tabindex="101" value="User Name" />
		<input type="password" class="textbox" tabindex="102" name="vb_login_password" id="navbar_password" size="10" />
		<input type="text" class="textbox default-value" tabindex="102" name="vb_login_password_hint" id="navbar_password_hint" size="10" value="Password" style="display:none;" />
		<input type="submit" class="loginbutton" tabindex="104" value="Log in" title="Enter your username and password in the boxes provided to login, or click the 'register' button to create a profile for yourself." accesskey="s" />
			</div>
		</div>
	</fieldset>
	<div id="remember" class="remember">
		<label for="cb_cookieuser_navbar"><input type="checkbox" name="cookieuser" value="1" id="cb_cookieuser_navbar" class="cb_cookieuser_navbar" accesskey="c" tabindex="103" /> Remember Me?</label>
	</div>
 
	<input type="hidden" name="s" value="" />
	<input type="hidden" name="do" value="login" />
	<input type="hidden" name="vb_login_md5password" />
	<input type="hidden" name="vb_login_md5password_utf" />
</form>

So if you model your form after that one (i.e. use the same <form> and <input> tags but change them to display like you want), I think it should work the same and the built-in login.

Note that the above was copied from the HTML page source and not the template, because I wasn't sure if you were using templates for your new login page. If you are, then it's better to go to the navbar template and find the template code for the above. In the above code I removed the "securitytoken" hidden field because there's no way to set that in a static page, but if you use templates you should include it.