two field table: field1, field2, how to add a third one with the auto-generated value replace(field2,'channel','AAAA')?

[zxo102 ouyang <zxo102@xxxxxxxxx>]

Hi evreyone,

   I have a table with two fields

 

   field1    field2

    1         1channel

    2         2channel

    3         3channel

 

Now I want to add the third one with the value replace(field2,'channel','AAAA') like

 

   field1    field2           field3

    1         1channel    replace(field2,'channel','AAAA')

    2         2channel    replace(field2,'channel','AAAA')

    3         3channel    replace(field2,'channel','AAAA')

 

The field3 must be done automatically after a user input data into field1 and field2.

 

Any ideas?   Thanks a lot.

 

ouyang