Javascript function need allow numbers, dot and comma

Question

I need to create a function to allow numbers dot and comma. So anyone corrects the following function

function on(evt) {
  var theEvent = evt || window.event         


        

Answer 1

No need for JavaScript:

Modern browsers will handle this perfectly.

If you want to specifically allow commas as thousand separators and a single decimal point, try this:

... pattern="\d{1,2}(,\d{3})*(\.\d+)?" ...

Note that I am firmly against blocking user input. They should be able to type what they want, and then told if they enter something invalid.