Motorola Mobile Workstation 520 Application Developer's Manual page 45

40 MW-520 Application Developer's Guide
This function has four parameters, of which only the first and third are used here.
The first parameter is a virtual-key code and the third parameter indicates whether
the key is pressed or released. By default, the third parameter is zero, which
means Key Down.
The following is an example of the use of the
keybd_event(VK_SHIFT, 0, 0, 0);
keybd_event(VK_SHIFT, 0, KEYEVENTF_KEYUP, 0);
The second call to keybd_event is required to indicate to the
operating system that Shift key is no longer pressed.
Note
function:
keybd_event ()