I used this netwatch command when google.com ping is down
:local dumplist [/ip hotspot active find]
:foreach i in=$dumplist do={
/ip hotspot active remove $i
}
BTW, this is the link where I found this script: http://wiki.mikrotik.com/wiki/Notify_your_customers_internet_is_down,_monitor_connectivity
this removed all active hotspot users.
How can I remove all except some users exactly two users! 
Please help me
MikroTik Version: 2.9.27