how do i connect a db to report so it can pull information from it to the crystal report?

i am making a view which just views reports.  The thing is that some of these reports require access to a database, which it doesnt seem to connect to.

I am pretty much doing as follows:

DSN = "XXXX"   ' <-- this is an ODBC connection
if (DSN exists):

connect to the DSN

attach DSN to .rpt somehow

show the report

else:

        messagebox.show("You are on an Invalid computer to access these files")

endif

I was trying to do this, but am unable to connect the database to my report, so when it runs, the drop down boxes are not populated in which to select people whom to add to the report during runtime.