Autofill based on Account Number

Hi guys, I have a form where you are required to enter a clients details, what I would like to do is when the user types in the clients account number (The unique identifier for the account) it will fill in all the other fields such as; client name, address line 1, address line 2, address line 3 etc etc I have tried a combo box but I don't want a drop down box I want to be able to type and have it appear when I click out of the box
I have tried this in the control source;
Tables!tblClientDetails!Account Number.column(5)
where column 5 is address line 1

Can anyone shed some light?