How do I convert existing lowercase data to uppercase in Access 2000? I used the following which did not work?

UPDATE HousingTowns
SET tMunis=UPPER(tM unis);

"HousingTow ns" is the table name.
"tMunis" is the field name in which the lowercase text is stored in 154 000 rows.

I get the error message "Undefined function 'UPPER' in expression".