I am creating an app that has 2 forms (Entry Form and Teams).  In the "Entry Form" is a lookup field to the "Teams" report.  In "Entry Form" I also have a drop down list that could have the same values as the "Teams" report, not sure which is best to use but I am guessing the lookup field?  

What we want to happen is that when a user selects a TEAM on the "Entry Form" app for that TEAM to be disabled, or no longer able to be selected by another user.  

So if we publish this app to a webpage and invite 10 users to the app and each has to select a TEAM, user #1 will have 10 choices, that user #2 will only have 9 choices, user #3 will only have 8 choices, etc...

Thanks!

P.S.  I found a forum on Dynamic List but not sure this is my problem?