I want to write a plugin that must execute instructions step by step, so i use this method:

for (i = 0; i < 10; ++i)
Sendshortcut(PM_MAIN, 0, WM_KEYDOWN, 0, 0, VK_F8);

but it doesn't work, it can only execute one time(the left 9 times are ignored), why this happened? Can anybody give me some suggestions?

Thanks!

Because while the first shortcut is executed asyncronously, the rest (9) are run. You have to queue your requests.