Need help adding new columns/fields to the grid on the SalesPostingHistory form

Hello,

I'm new to DAX and I'm having trouble trying to figure out how to add new fields to a form. The form is called SalesPostingHistory and is located under - Accounts Receivable > Inquiries > Journals > Invoice. The two new fields I'm trying to add are: CreatedDateTime, CreatedBy. Here's what I tried so far: Right-Clicked on the form > setup, then I clicked "Add Fields" to the OverviewGrid. I wasn't able to see the two fields I need added.

I'm using Dynamics AX 2009. Any help would be greatly appreciated.

Thanks,

Rex