How to post data to third party dll?

Question

When i am trying to post data to dll  on live server then its redirecting to same page.

i have used following code

<form id="simForm" runat="server" method='post' action='https://secure.authorize.net/gateway/transact.dll'>


i have used same code for local server so its working fine

if any one know about it please give me solution for that..