xdotool send keystroke even when windows does not have focus

I've written the attached script in order to keep my external monitor alive while I'm not typing on it. I'm using fvwm, and have multiple named windows open. The script successfully types A every second to a named window, but it only works when the window has focus. How can I modify the script so that it continues to type even when the window doesn't have focus? Presumably I can use the behave option to xdotool somehow to do this, but the syntax for xdotool with behave seems impossibly arcane #!/bin/bash tmpTITLE=STARTUP0 if [ $# -eq 1 ] ; then tmpTITLE=$1 fi Window=wmctrl -lp | grep $tmpTITLE | cut -d" " -f 1 while sleep 1 ; do xdotool key --window $Window A; done