Pending messages

[Richmond]

So . . . here I am with a stack containing 2 buttons: 'B' and 'cancel',

and a field 'KNT':

Btn 'B' contains the script:

on mouseUp
    put 1 into KK
    repeat until KK = 25
    set the vis of btn "B" to false
    wait 20 ticks with messages
    set the vis of btn "B" to true
    wait 20 ticks with messages
    put KK into fld "KNT"
    add 1 to KK
    end repeat
end mouseUp

I want to stop the action started by btn "B" using a script
in btn "cancel" but cannot work out how to do that.

Richmond.