Efficient validation of array contents

[Pete Helgren <Pete@xxxxxxxxxx>]

I have a set of five values that come in from a prompt screen that can 
be from 1 to 5 and can only occur once.  That is, if a value is entered 
(not 0) , it must be a value from 1 to 5 and there cannot be duplicate 
values.

The fields are loaded into an array:

    DUDFS             DS
    D  FTSUDF1                       1S 0
    D  FTSUDF2                       1S 0
    D  FTSUDF3                       1S 0
    D  FTSUDF4                       1S 0
    D  FTSUDF5                       1S 0
    D  UDF                                Like(FTSUDF1) Dim(5)
    D                                     overlay(UDFS)

and then I loop through them:

         for LoopCount =  1 to 5;
           if UDF(LoopCount) <> 0;
            // Check to make sure the value is between 1 and 5
               if UDF(LoopCount) > 5;
                     //Error occurs
               endif;
            // Check to make sure the number only occurs once
               ??
           endif;
        endfor;

I can't think of an easy way to check the occurrence of the number in 
the array.  The brain is just a wee bit stretched tonight.

A quick solution?

Thanks,

Pete Helgren