Join two fields

[deepcec9]

I would like to join autonumber field and a text and save it to another field.
For example
Autonumber test_field
1 w1
2 w2
3 w3
44 w44

tried "W"+""[autonumber] in test_field format, but its not working. Please help
Thanks in advance

 

[arnelgp]

"W" & Ltrim(Cstr([AutoNumber]))

 

[deepcec9]

Please find the attached screen shot of the error

 

[arnelgp]

from where are you executing this expression?

 

[deepcec9]

Tried it in table->format...
Where should it be executed?

 

[smig]

what for ?