How to Handle This Exception

Dear Friends

I am trying to use EXCEPTION HANDLING for the first time. I have used the following code in my program:

        Dim checkvalue As Boolean = False
        Try
            checkvalue = SaveImOrder()
            checkvalue = SaveImOrderDetails()
        Catch ex As Exception When checkvalue = False
            Exit Sub
        End Try
        (Rest of the code)

In above mentioned functions I am actually saving records in tables and in case of any error returning "FALSE" back here ... Then I need to catch this FALSE value to exit SUB .... However the code is not working and I am unable to track my mistake .. Please help or advice something better

Best Regards

ZEE