script to disable and enable download

Hi all
Following script to disable downloading when the number of users in reg -table are 20 and above and enable it at less than.

/ip proxy access
add action=deny comment=1 disabled=no path=.exe
add action=deny comment=1 disabled=no path=
.rar
add action=deny comment=1 disabled=no path=.zip
add action=deny comment=1 disabled=no path=
.mp3
add action=deny comment=“” disabled=no path=*.wav
/system scheduler
add comment=“” disabled=no interval=5m name=“disable download” on-event=“:if ([
:len [/interface wireless reg find]] >=20) do={/ip proxy access enable [/ip
proxy access find comment=1]\r
\n}” start-time=startup
add comment=“” disabled=no interval=5m2s name=“enable download” on-event=“:if (
[:len [/interface wireless reg find]]<=19) do={/ip proxy access disable [/i
p proxy access find comment=1]\r
\n}” start-time=startup