I was wondering if it is possible for me to have a window pop up when a certian field is set to true. (E.g. if( get (CurrentDate) > 89 > oil change date ; Pop up ; "" ) ) or somethinjg like that. My calculation is probably off, but I was just using an example and a quick one at that, but the basic idea is still there. Thanks in advance.

Try the EventScript Plug-in. It can trigger a script to run upon entry or exit of a field.

Website for more info is here!

How often do you want it to be envoked?

If its something you want envoked right after teh value in the field is changed then yes look into the EvenScript as Kent posted. However, if it is something you want to popup for example when you go the clients record and it is not something that requires immediate envoking, then you can just write it within the go to client record script etc.

I want it to look to a field and come up when a field is true. e.g. if (field = true, eventscript, "") something like that. I'm not even sure if this is an option. It would be nice though.

If that is the case, then you will definately need the EventScipt plugin. Check out the link that Kent posted.