repeat with i = 1 to 10
    repeat with j = 1 to 10
        put random(20) into aNums[i,j]
    end repeat
end repeat

repeat with i = 1 to 10
    repeat with j = 1 to 10
        if aNums[i,j] = 20 then
            put true into exitLoop
            exit repeat
        end if
    end repeat
    if exitLoop then exit repeat
end repeat

if exitLoop then
    put "20 found in" && i & comma & j
else
    put "20 not found"
end if