How to prevent invalid characters from being typed into input fields

Question

Onkeydown, I run the following JavaScript:

function ThisOnKeyDown(el) {
   if (el.title == \'textonly\') {
       !(/^[A-Za-zÑñ-\\s]*$/i).test(e         


        

Answer 1

You could easily do this in a single html line.

Like this to disallow spaces:

Or this to only allow numbers:

Just look up the unicode of any numbers you want to allow or disallow.