PopUp plugin

Hi
I want to make two popups on my site:
Please tell me what to do to make this happen: facebook like/share theme pops up and signup form theme. Is it possible? If yes, I wonder about pop ups collision. Here, what I mean.
Suppose, user clicks on my page, facebook like/share theme pops up
Facebook theme popup will sit there until user makes an action \”like/share\” (no matter how long that takes, no timer set)
After user makes an action with facebook theme, this signup form theme will popup and also remain until user makes an action \”subscribe\”

How long it would take for a user to respond to the first popup. I could be careful to allow enough time, but if a person gets distracted by an email or facebook message alert, for example, and temporarily abandons the form, the two pop ups will collide because of the user\’s delay in completing the first popup. I want this to be professional and go smoothly with no problems.