jQuery.fn.numeric = function(userWhiteList){
    // key white list
    var whiteList = [
        8, //backspace
        9, //tab
        46, //delete
        37, //left arrow
        39, //right arrow
        13 //enter
    ];

    if (userWhiteList !== undefined) {
        whiteList = whiteList.concat(userWhiteList);
    }

    $(this).keydown(function(event){
        var keyCode = event.keyCode;

        
        if($.inArray(keyCode, whiteList) != -1)
        {
            return true;
        }

        // key black list
        if(
            (keyCode > 57 || keyCode < 48)
            && (keyCode < 96 || keyCode > 105)
        )
        {
            return false;
        }
    });
};