Customization of Follow button


I am using Follow button of tweeter on my site. I want the image to be displayed as src=“” but this script does not allow you to authenticate user. How can i force the user to login with their tweeter credential.

Pls note that I know this functionality can be achieved with the following script -

Follow US

    <script src="" type="text/javascript"></script>

I hope you got my query right. Awaiting reply…