HTML text input allow only numeric input

Question

Is there a quick way to set an HTML text input () to only allow numeric keystrokes (plus \'.\')?

Answer 1

JavaScript code:

function validate(evt)
{
    if(evt.keyCode!=8)
    {
        var theEvent = evt || window.event;
        var key = theEvent.keyCode || theEvent.which;
        key = String.fromCharCode(key);
        var regex = /[0-9]|\./;
        if (!regex.test(key))
        {
            theEvent.returnValue = false;

            if (theEvent.preventDefault)
                theEvent.preventDefault();
            }
        }
    }

HTML code:

works perfectly because the backspace keycode is 8 and a regex expression doesn't let it, so it's an easy way to bypass the bug :)