Summarize & Total a field

[Dean Redding]

Hi,

I am not sure if this is the right forum, but I want to create a summary or calculation with the following:

I have records for clients that owe me payment on invoices completed, while the same clients have outstanding invoices to be completed.

I want to create a field where I can put in the customer details layout where it show's me what they currently owe.

The fields I want to use are: [fields]

[Client Name]

[Job Status] = Completed

[Amount Owing]

How can I create a total for each client when I look at the client records?

Many Thanks,

Dean