Assignment of Users to posistion

Hi All,

Please advise me with the following at earliest.

I have activated the standard workflow for the transaction FV60, so that the work item will be generated in the approver inbox for the release amount. I have done the settings, but iam stuck up at the transaction OBWF, it says to assign the users to the position or the organizational unit. I have created the Posistion in transaction code PO13 (Posistion in Business work flow), could you please let me know how to assign users to this position.