I have the algorithm but I need help with javascript syntax.
I'm trying to find if I have 1 'number#' or 2 'numbers##', then I need to
grab this number.

checkboxname = pfmABCD#:0
or
checkboxname = pfmABCD##:0

var1 = checkbox.name
for i=1 to var.length
var2 = mid(var1, i, 1)
If var2 = ":" then
If i = 9 then
var3 = mid(var1, 7, 1)
elseif i =10 then
var3 = mid(var1, 7, 2)
end if
end if
next