<form action="/dir/Twitter.aspx/InviteTweet" method="post">
<font face="Verdana" size="0">Usename: </font>
<input id="Text1" type="text" name="txtEmail" /><br />
<font face="Verdana" size="0">Password: </font>
<input id="Text2" type="password" name="txtPassword" /><br />
<br />
<input id="Submit1" type="submit" value="Sign in" />
the input <input id="Submit1" type="submit" value="Sign in" /> has no name
my php code
$url = "http://www.my site.com/dir/Twitter.aspx/Index"; // This page contains Login form
$postfields='txtEmail=username&txtPassword=password';
$ch=curl_init($url);
curl_setopt($ch,CURLOPT_RETURNTRANSFER,true);
curl_setopt($ch,CURLOPT_FOLLOWLOCATION,true);
curl_setopt($ch, CURLOPT_POST, 1);
curl_setopt($ch, CURLOPT_POSTFIELDS, $postfields);
$page=curl_exec($ch);
curl_close($ch);