Multiple use fields in a form

[Kisageru]

Hi guys,
I currently have a database where I can make an invoice by filling out all the required fields.
However when it comes to choosing a client to send the invoice to I currently have it set so when I select an option from a combo box it fills in the fields automatically, however I would like it so I could also enter a new user in the fields and have it saved to the Clients table and then have it selectable from the combo box at a later date.
How would I go about having a multi use field like this? I've tried doing =[cmboAccNo].[column](1)!ClientName to see if it can reference both fields, but I thought this was a silly idea and presumed it needed some VBA code, which I am terrible with

The current fields for the client table are;

pk_ClientAccountNumber
ClientName
ContactFirstName*
ContactLastName*
AddressLine1
AddressLine2
AddressLine3
City
Postcode
PaymentTerms
ContactNumber*
ContactEmail*
Fields with a * aren't used in the form but for billing inquires at a later date

Also I have the Query [Forms]![Create Invoice]![InvoiceNumber] which I use to open a report based on the invoice number I type in, which in turn shows a completed invoice, however in the dialogue box that pops up it shows the query code, is there any way I can change it to show something like "Please enter an invoice number" instead of the query code

[alansidman]

this link should get you started in the right direction

Microsoft Access tips: Adding items to a combo/list box

[Kisageru]

Thankyou Alan,
I used the "Using another event to open a form" method and this seems the easiest way of doing it

[Kisageru]

Sorry for the double post. I can't edit my posts but,
It's probably worth mentioning that on the double click event I changed:

        Else
            'Combo was blank, so go to new record.
            RunCommand acCmdRecordsGoToNew
        End If

to

        Else
            'Combo was blank, so go to new record.
            DoCmd.GoToRecord , , acNewRec
        End If

As the the original part was throwing up errors but the new code seemed to fix it.

I am also having an error with a Save and Close button. When I click it an error message appears stating "Error 2467: The expression you entered refers to an object that is closed or doesn't exist."
and then only has an OK button, this only seems to appear when I type something into the form then try to save and close. However the data is still saved to the table and can still be selected from the combo box

[alansidman]

Post your code for the Save and Close Button.

In the meantime, google your error code.

[Kisageru]

The button is only a built in macro, so I can't figure out why it's giving me errors I've googled the error code and it seems to be a bug but I don't see any work around for it