Opening forms in other thread

Background threads are perfect for big calculations in background, but I'm unable to create form that actually works in other thread. Either it closes emidietly, or, when I put thread proces in a infinite loop, then opened form is "stucked", busy icon appears when I move mouse over it, and it doesen't initialize it's components. This is what I'm trying to do: I want to start another thread in background that will go to the database every n-minutes, and get data from it, check if there is any new data since the last update, and show Popup-style form(s). Now, I could do it with timer in one thread, but what if that process of getting new data from database takes long? I don't want it to slow down the main application....... I downloaded one example that worked with popup messages in other thread, but I just couldn't understand why it worked there... So if anyone could give me general tips and tricks, "how to do it", I would appricate it .... Thanks in advance..