[Javascript] Number validation with digit grouping

[javascript@xxxxxxxxxx (Tobias Barlind)]

Does anyone have a good snippet that validates a string of numbers that
has digit grouping?

I.e "12,200.50"

isNaN returns true on this.

And I can't just simply remove all "," because I have to deal with
different languages having different decimal signs like "," instead of
"." :)

//B