How update yes/no field in an unbound table

I have an unbound form which contains a combobox.  After the user has selected a record from the combobox I want the user to then be able to click a command button which I also have on the form.
When the user clicks this command button I want a field in a record in tblOutpurchase to be updated. The field name is "Complete" which is a yes/no field.  It is false by default and I want it changed to true.

I'm not sure of the syntax for the onclick event of the command button but it has to be something like:


update tblOutpurchase.complete = true where JobN = Me.cboJobN

Can someone help?

--Steve