VBA and ACCESS question - URGENT PLEASE HELP

[hooloovoo]

I need some help on some vba code, and its pretty urgent.

I have two tables, T1 and T2.

I need to access a field from T1, do a little calculation on it, and add that value to a text field which then puts that value in T2.

Can someone please help by giving me the VBA code for use in MS ACCESS which selects a field from another table, and select a field and record where some other field, say key, equals some other value?

var = select from T1 field F1 where F1 = C1

thanks