search for url in textarea as user types then trigger function

What i'm trying to do is search a textarea while the user is typing for a url beginning with http:// then if found, fire a function, and stop searching for an url.

I know this can be done with jQuery but I'm having quite a few issues with :contains, indexOf, regex, etc.

heres a bit of code to explain what I'm trying to do!

$(document).ready(function() {    
var body = $('#example').attr('value');               
body = encodeURIComponent(body);
var urlregex = new RegExp("^(http:\/\/www.|http:\/\/www.|www.){1}([0-9A-Za-z]+\.)");
if(urlregex.test(body)) {
        $("#new_url").html('../images/loading.gif" border="0">');
            $.ajax({
                type: "GET",
                url: "get_url.php",
                data: "entry="+body,
                cache: false,
                success: 开发者_C百科function(html) {
                    $("#new_url").html(html);
                }
            });
            return false;
  }
  return(false);
}
});

Thanks for all your help...

You code looks a little messy. Is this what you are after?

var myFunction = function() {
    console.log('URL found.');
}
$('textarea').bind('keyup', function(e) {
    if ($(this).val().match(/http:\/\//)) {
        myFunction.call(this);
        $(this).unbind('keyup', arguments.callee);
    }
});

Below function gets all the urls found in textarea

var myFunction = function() {
    console.log('URL found.');
}

$("textarea").keypress(function (e) {
    if ((e.which && e.which == 32) || (e.keyCode && e.keyCode == 32)) {
        if ($(this).val().match(/https?:\/\//)) {
            myFunction.call(this);
        }
    }
});