Write to two tables in one form

[fluidmind]

Hi There!

I have two tables 'table1' and 'table2'. They both have 'clientnumber' as the keystring.

I want three textboxes in one form:
1) Textbox1 bound to 'clientnumber' (key) in table1
2) Textbox2 bound to 'clientname' in table1
3) Textbox3 bound to 'xxxxx' in table2 where 'clientnumber' is the same as in textbox1.

My question is, how do i make textbox number 3???