Allow only numeric value in textbox using Javascript

Question

I want to allow only numeric values to be entered into the text and if user enters alphabetic character it should warn the user. Any suggestion for optimized and short javas

Answer 1

Here is a solution which blocks all non numeric input from being entered into the text-field.

html

javascript

var input = document.getElementById('numbersOnly');
input.onkeydown = function(e) {
    var k = e.which;
    /* numeric inputs can come from the keypad or the numeric row at the top */
    if ( (k < 48 || k > 57) && (k < 96 || k > 105)) {
        e.preventDefault();
        return false;
    }
};​