Windows security credentials pops up when making CRM service call

Hi Friends,

Please help here.

I'm calling CRM service from the C# code. Every time it popups the Windows security credentials dialog for username and password?

It is happening on the line service.Create method call.

I have made service initialization where user credentials are already specified.

Below is the popup i'm getting when the service is called.

Your reply may help me. Looking for your support.

Thanks,

Nithya