>>I call a UDF called getdate from a form and when it processes a seek() with parameters it gives me the error "Thisform ......"
>>If I ignore the error the other times I call the UDF it's all OK.
>>I call this UDF even from other forms with the same statements and it never gives me any problem.
>>Any suggestion ?
>>Thanks to all
>>Alessio
>>
>>My English is getting worse
>
>UDF should contain direct reference like frmMain.Property1, and this is strange that you didn't get errors in other places.

I finally found the error .
In my UDF I used a table previously open in the calling form.
I filtered the table with a thisform.property and it gave me the error.
Thanks to all anyway.
alessio