Capitalize Procedure exercise

I keep getting a
Run-time error '94': Invalid use of Null
when I run this exercise.

Debug goes to this line: rec(strFld) = UCase$(rec(strFld))

My code is below.

Function Capitalize(strTable As String, strFld As String)

Dim db As Database
Dim rec As Recordset

Set db = CurrentDb()
Set rec = db.OpenRecordset(strTable)

Do While Not rec.EOF
    rec.Edit
    rec(strFld) = UCase$(rec(strFld))
    rec.Update
    rec.MoveNext
Loop

Capitalize = True

End Function

I call the procedure with
? capitalize ("tblCompany", "Country")

When I step through it the locals window shows

Expression: Capitalize
Value: empty
Type: variable


Thanks for any help

I copied your code verbatim, executing it against the database off the Access 2002 VBA cd, and it executed fine.

I did also however go into the table tblCompany and cleared out the country name in a couple of records. When I ran the code again, I do get the error.

My assumption is that this is either a normal error returned by the UCase function if the field it encounters is null, or, that there is a level of error checking being performed, which will return errors in this type of situation (my thought being the level could be changed to not return errors when a null field is encountered).

I'd double-check the records in tblCompany. You could also type a Debug command in the immediate window to determine on what record the error is occurring. For example

debug.Print rec("CompanyID").

I hope this helps.