Well not even really reviewing your code I get this back from SANITY.UDF

Code:
Warning: Global variable declared as Local.
              Variable Name: $un
                In function: EnumerateUsers
         Referenced on line: 15
    Global declared on line: 5

Warning: Global variable declared as Local.
              Variable Name: $ou
                In function: EnumerateUsers
         Referenced on line: 15
    Global declared on line: 5

Warning: Global variable declared as Local.
              Variable Name: $handle
                In function: EnumerateUsers
         Referenced on line: 19
    Global declared on line: 5

Warning: Undeclared variable.
              Variable Name: $
                In function: Main
         Referenced on line: 2

Warning: Undeclared variable.
              Variable Name: $
                In function: EnumerateUsers
         Referenced on line: 20

Warning: Undeclared variable.
              Variable Name: $myOU:
                In function: EnumerateUsers
         Referenced on line: 31

Warning: Variable referenced inside string.
              Variable Name: $myOU:
                In function: EnumerateUsers
         Referenced on line: 31

Warning: Undeclared variable.
              Variable Name: $ou:
                In function: EnumerateUsers
         Referenced on line: 31

Warning: Variable referenced inside string.
              Variable Name: $ou:
                In function: EnumerateUsers
         Referenced on line: 31

Warning: Undeclared variable.
              Variable Name: $element:
                In function: EnumerateUsers
         Referenced on line: 31

Warning: Variable referenced inside string.
              Variable Name: $element:
                In function: EnumerateUsers
         Referenced on line: 31

Warning: Variable referenced inside string.
              Variable Name: $users
                In function: EnumerateUsers
         Referenced on line: 31

Warning: Variable referenced inside string.
              Variable Name: $element
                In function: EnumerateUsers
         Referenced on line: 31

Warning: Variable referenced inside string.
              Variable Name: $ouStore
                In function: EnumerateUsers
         Referenced on line: 48

14 warnings encountered in 65 lines.