Irule to disable ASM

i have 2 servers i want to keep forwarding traffic to server1 & in this case ASM should be disabled once server1 is down , i want to forward to server2 & enabel ASM checking if server1 is online again , i should forward to it & disable ASM as it was initially Created VS , Created two pools , each with one pool member under it Below Irule is now working , once ASM is enabled ON VS it is always enabled & never goes disabled again when serevr1 comes back online

when HTTP_REQUEST {

Check Pool-1 status , if Up forward to it & make sure ASM is disabled Otherwsie Forward to Pool-2 & enable ASM

if { [active_members Pool-1] >= 1 } {

                                           pool Pool-1
                   ASM::disable

        } elseif {[active_members Pool-2] >= 1  } {

                                                  pool Pool-2
                          ASM::enable policy-name

                        }

}