javascript - Code doesn't work in IE8 -

i'm using following code remove "http://" , "https://" user entered/pasted url in textbox:

$('input.url-input').change(         function()        {            var textbox = $(this);             if (textbox.val().indexof("http://") == 0)                textbox.val(textbox.val().substring(7));             if (textbox.val().indexof("https://") == 0)                textbox.val(textbox.val().substring(8));         }); 

my problem works in browsers, including ie9 & ie10, not in ie8.

i'm new javascript , appreciate help.

many in advance!

works in ie7,8 use jquery <= 1.10.x not 2.0.x

$('input[type=text].input-url').change(    function(event) {       var $input, url;        $input = $(this);       url = $input.val();       $input.val(url.replace(/^(http(s)?:\/\/)/i,''));            }); 

or short

  $('input[type=text].input-url').change(       function(event) {       $(this).val($(this).val().replace(/^(http(s)?:\/\/)/i,''));   });