mathematical function

[Excellent1]

I am working with a table in Access that contains

Tracking number, invoice number, customer number, box
number, freight charge, ship via rate. we have two
customers ABC001 and DEF002 that have special freight
charge rules. for ABC001 their freight charge is 4.50
less than the value in freight charge and for DEF002
their freight charge is 2.50 less than the value in
freight charge. How can I code a function to pass
through access and make these changes for the given
customers? thank you in advance

 

[Excellent1]

thank you very much.....it works

One more question....how can I parse a field? the ship via rate field contains the way they want the product shipped (UPS, UPS blue, UPS collect, etc) I need an if statement that any time the letter "c" appears in the ship via rate field that freightcharge is changed to 0

 

[khexcel]

Use the INSTR function

Example:

iif(instr([ship via field],"C"),[freight]=0)