When you press the A/B key or one of the 4 programmable keys on the AnyTone AT-778UV mic/remote, that function remains selected and using he normal channel up/down keys cycles through the options of the selected function. This behaves just like the volume knob on the base unit. On the base unit you can press in on the volume knob to choose the option and return the volume knob to the normal function of adjusting the volume. There is no corresponding "select" button on the mic/remote. So, once you have pressed a function key, used the up/down keys to choose the option you want, how do you "select" that option and return the up/down keys to their normal operation?