WaitKeyDown>key_to_wait_for
WaitKeyDown pauses execution until the specified key is pressed. For an ordinary character key specify the character of the key. For other keys use the virtual key code preceeded by VK:
WaitKeyDown>H - waits for the H key to be pressed
WaitKeyDown>VK101 - waits for virtual key code 101 (Numpad 5) to be pressed.
A list of virtual key codes can be found here: http://www.mjtnet.com/vkcodes.htm
Abbreviation : WKD
See also: Wait, WaitWindowOpen, WaitWindowClosed, WaitCursorChanged, WaitPixelColor, WaitReady