vb如何自动登陆这个网站?

html代码如下:

地址:http://china.alibaba.com/member/signin.htm?done=http%3A%2F%2Fchina.alibaba.com%2Foffer%2Fmanage.htm%3Fasker%3DATC%26needsignin%3D1%26tracelog%3Dalitalk_free_offermanage2



HTML code:

</div>
<div class='loginbox'>
<div>
<span class='boldfont'>登录名</span>
<span>
<input id='loginid' class="inputwd1" type="text" name="LoginId" size="15" maxlength="20" value="sistom" tabindex="1" />
</span>
<span><a href="http://china.alibaba.com/member/retrieve_login_id.htm?tracelog=signin_retrive_id">找回登录名</a></span>
</div>
<div class="adjustml">
<span class='boldfont'>密码</span>
<span><input class="inputwd1" type="password" name="Password" maxlength="20" tabindex="2" id='pwdid' /></span>
<span><a href="http://china.alibaba.com/member/retrieve_password.htm?tracelog=signin_retrive_pass">找回密码</a></span>
</div>