You've got some problems there, they all appear on debugscript.
-- client side:
theWindow = guiCreateWindow(420, 210, 433, 320, "Jetpack giver By Robbster", false)
guiWindowSetSizable(theWindow, false)
theButton = guiCreateButton(122, 123, 188, 87, "Give yourself Jetpack", false, theWindow)
guiSetVisible(theWindow,false)
function openWin()
if guiGetVisible(theWindow) then
guiSetVisible(theWindow, false)
showCursor(false)
else
guiSetVisible(theWindow, true)
showCursor(true)
end
end
bindKey("F5", "down", openWin)
function giveJetpack ()
triggerServerEvent ( "givejet", getLocalPlayer() ) --try root or source if no work
end
addEventHandler ( "onClientGUIClick", theButton, giveJetpack, false )
-- server side:
function Jetpackgiver ( )
givePedJetPack ( source )
end
addEvent( "givejet", true )
addEventHandler( "givejet", getRootElement(), Jetpackgiver )