>OOPS ...
>Correction: varType(myfield) correctly returns a U when 'myfield' field is non existent.

This is not a reliable check, because you may have variable myField defined...
vartype(MyTable.myField) would generate an error, as Marcia pointed out... So, type('MyTable.myField') is the correct solution if your table is a free table. Otherwise INDBC() function could be used instead.