There are many settings in the SCLogin module parameter that need to be configured to display SCLogin as a modal popup - Login View Settings, Modal Style, Load JQuery, etc. If you are having trouble with these settings displaying the popup, please clarify in more detail what issues you are encountering and on what specific URL it is happening. Your question is too vague for me to understand what problem you are having.
-Melissa
modal pop-up for sclogin
