You should try settings ur dialog up like:

on *:dialog:CMP:*:*: {
if ($devent == sclick) {
if ($did == 13) {
  set %CMPchan1 $$?=\"Enter Channel Name\"
  did -a CMP 5 %CMPchan1
}
elseif ($did == 14) {
  set %CMPchan2 $$?=\"Enter Channel Name\"
  did -a CMP 6 %CMPchan2
}
elseif ($did == 15) {
  set %CMPchan3 $$?=\"Enter Channel Name\"
  did -a CMP 7 %CMPchan3
}
}