function aBind (   ) 
        if ( eventName == 'onClientVehicleEnter' ) then 
            bindKey ( 'F5','down',abrir ) 
            outputChatBox ( '#ff0000painel f5.', 124, 252, 0, true ) 
        else 
            unbindKey ( 'F5','down',abrir ) 
    end 
end  
addEventHandler ( 'onClientVehicleEnter',root,aBind ) 
addEventHandler ( 'onClientVehicleExit',root,aBind ) 
 
Easier for you and fixed some fucked things !