Regex Replace anything but numbers and lowercase

Question

I have an input which I am binding to keyup()

On each keyup, I want it to:

1. disallow any characters that are not a number, a letter, or a dash, and
2. replace any uppercase characters with lowercase ones.

Regex makes my head explode, any help?

$('.my-input').keyup(function() {
    this.value = this.value.replace(/[^0-9a-z-]/g,/[0-9a-z-]/g);
});

Answer 1

this.value = this.value.toLowerCase().replace(/[^0-9a-z-]/g,"");