var ip: LPINPUT
#ip.itype = INPUT_KEYBOARD
ip.u1.ki.wScan = 0; # hardware scan code for key
ip.u1.ki.time = 0;
ip.u1.ki.dwExtraInfo = 0;

ip.u1.ki.wVk = 0x41; # virtual-key code for the "a" key
ip.u1.ki.dwFlags = 0; # 0 for key press
SendInput(1.UINT, ip, sizeof(INPUT).int32);