// Ctrl/Alt/Shift
if (keynum == 16) guac_keyboard.modifiers.shift = false;
else if (keynum == 17) guac_keyboard.modifiers.ctrl = false;
// Ctrl/Alt/Shift
if (keynum == 16) guac_keyboard.modifiers.shift = false;
else if (keynum == 17) guac_keyboard.modifiers.ctrl = false;