Limit input to numbers and . on input field

Question

Following on from another question I asked, i really didnt seem to be getting anywhere. Due to my ineptitude. I chose the guys answer because , well he answered my question.

Answer 1

You could, in the change event of the input, check if the number format is OK. This code will try to get the number and remove anything else: (I'm assuming you use jQuery, if not, please do)

$('#price').change(function() {
    $(this).val($(this).val().match(/\d*\.?\d+/));
});

See it working here.

EDIT: if you don't have jQuery, this code does the same (at least in Chrome):

document.getElementById('price').onchange = function() {
    this.value = this.value.match(/\d*\.?\d+/);
};

EDIT 2: not sure if I follow, but you could add this too to prevent letters and other characters before the change event:

$('#price').keypress(function(event) {
    var code = (event.keyCode ? event.keyCode : event.which);
    if (!(
            (code >= 48 && code <= 57) //numbers
            || (code == 46) //period
        )
        || (code == 46 && $(this).val().indexOf('.') != -1)
       )
        event.preventDefault();
});