[ SOLVED ]
apt-get install xdotool
and add this to your .jwmrc:
Code:
<Key mask="A" key="F1">exec: xdotool set_desktop_for_window $(xdotool getactivewindow) 0 </Key>
<Key mask="A" key="F2">exec: xdotool set_desktop_for_window $(xdotool getactivewindow) 1 </Key>
<Key mask="A" key="F3">exec: xdotool set_desktop_for_window $(xdotool getactivewindow) 2 </Key>
<Key mask="A" key="F4">exec: xdotool set_desktop_for_window $(xdotool getactivewindow) 3 </Key>