Passing Parameters from Login to Form to another Form in MX or Studio 8

I may be real dense but I haven't been able to figure out how to get my user parameters to filter a database to get the results of just that users items in the database.

I have users.  I have input to database of oil wells.  I have all the wells in one table I have the users in another table.  I want to send a user to a page from login that gives them the choice to open pages about any one of their wells.  I am using a menu/list box and need to have only the user's wells appear in the box, not all of them which is currently happening.  I know I am not passing parameters and queries correctly but I can't seem to figure it out.  Help with this would be great.