A cell phone prevents inadvertent dialing or answering of the cell phone by detecting a low light condition consistent with the phone being in a pocket, purse or the like. The ability to use the phone unencumbered in low light situations is provided by using the low-light detection not to disable the phone but to cause a user prompt that requests a user decision on rejecting the phone activity. The user input is tailored to a particular predetermined button for either condition to ensure the results of this prompt are unlikely to be satisfied by an accidental keypress.