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

So simple....

// In a JavaScript function (can use HTML or PHP).

function isNumberKey(evt){
    var charCode = (evt.which) ? evt.which : evt.keyCode;
    if (charCode > 31 && (charCode < 48 || charCode > 57))
        return false;
    return true;
}

In your form input:

With input max. (These above allows for a 12-digit number)