To obtain user approval of network transactions at different levels of security, a network site selects a form in which a transaction with be presented to the user from a group of transaction presentation forms including presentation of the transaction in a browser pop-up window on a user network device, in a security software application window on the user network device, and in a security application window on another user network device. The network site also selects a type of approval of the transaction required from the user from a group of transaction approval types including approval requiring no action by the user after presentation of the transaction, the user to actively approve the presented transaction, and the user to sign the presented transaction. The transaction, the selected transaction presentation form, and the selected type of user transaction approval, are transmitted to obtain approval of the transaction by the user.