Hide A DIV if screen is narrower than 1024px

Question

I found (from this question - Hide div if screen is smaller than a certain width) this piece of coding

  $(document).ready(function () {

    if (screen.width < 1024) {
        $("#floatdiv").hide();
    }
    else {

        $("#floatdiv").show();
    }

});

The only problem is, I cannot seem to get the code to work, I only need to code to work for IE, I'm going to use Media Queries for other (newer) browsers. Any hints/tips on where I'm going wrong?

So far I have <div id="floatdiv">

Then at the end of that div (where is closes) I have

<!--[if lt IE 9]>
<script type="text/javascript" src="http://dl.dropbox.com/u/17087195/website/sidebar_size.js"></script>
<![endif]-->

In my header I have <script type='text/javascript' src='http://www.itsdaniel0.com/wp-includes/js/jquery/jquery.js?ver=1.4.4'></script>

And I still cannot get the code to work (testing in IE8) Am I still going wrong somewhere?

Update I do have another piece of jQuery linked, could this be causing the issue? Here is the full piece of coding below

<div id="floatdiv">

<div class="floating-menu">

<iframe src="http://www.facebook.com/plugins/like.php?href=http%3A%2F%2Fwww.itsdaniel0.com%2F2011%2F03%2Funicorns-are-cool%2F&amp;layout=box_count&amp;show_faces=true&amp;width=55&amp;action=like&amp;colorscheme=light&amp;height=65" scrolling="no" frameborder="0" style="border:none; overflow:hidden; width:55px; height:65px;" allowTransparency="true"></iframe>

<br /><br /><a href="http://twitter.com/share?url=http%3A%2F%2Fid0.me%2Fj0&amp;counturl=http://www.itsdaniel0.com/2011/03/unicorns-are-cool/" class="twitter-share-button" data-text="Unicorns Are Cool" data-count="vertical" data-via="itsdaniel0 #itsdaniel0">Tweet</a><script type="text/javascript" src="http://platform.twitter.com/widgets.js"></script>

<br /><br />

<script src="http://widgets.fbshare.me/files/fbshare.js"></script>

</div>

</div>

<script type="text/javascript" src="http://dl.dropbox.com/u/17087195/website/sidebar.js"></script>

<!--[if lt IE 9]>

<script type="text/javascript" src="http://dl.dropbox.com/u/17087195/website/sidebar_size.js"></script>

<![endif]-->

Error Message

Webpage error details

User Agent: Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 5.1; Trident/4.0; chromeframe/10.0.648.133; .NET CLR 1.1.4322; .NET CLR 2.0.50727; .NET CLR 3.0.4506.2152; .NET CLR 3.5.30729; OfficeLiveConnector.1.5; OfficeLivePatch.1.3; .NET4.0C; .NET4.0E; InfoPath.2) Timestamp: Sat, 12 Mar 2011 11:31:32 UTC

Message: Expected identifier, string or number Line: 140 Char: 1 Code: 0 URI: www.itsdaniel0.com/2011/03/unicorns-are-cool/

Message: Object doesn't support this property or method Line: 16 Char: 1 Code: 0 URI: dl.dropbox.com/u/17087195/website/sidebar_size.js

Message: 'twttr.anywhere._instances' is null or not an object Line: 1 Char: 5207 Code: 0 URI: platform.twitter.com/anywhere.js?id=6vIPELyEeU5vcSc3c0Q5w&v=1

Message: 'twttr.anywhere._instances' is null or not an object Line: 1 Char: 5207 Code: 0 URI: platform.twitter.com/anywhere.js?id=6vIPELyEeU5vcSc3c0Q5w&v=1

Removed http from URLs due to "low rep" error

Answer 1

OLD ANSWER USING JQUERY:

//the function to hide the div
function hideDiv(){

    if ($(window).width() < 1024) {

            $("#floatdiv").fadeOut("slow");

    }else{

        $("#floatdiv").fadeIn("slow");

    }

}

//run on document load and on window resize
$(document).ready(function () {

    //on load
    hideDiv();

    //on resize
    $(window).resize(function(){
        hideDiv();
    });

});

EDIT: Please note that now there is much more cross browser support for css3 media queries it would be much more effective to use those rather than javascript.

USING CSS.

/* always assume on smaller screen first */

#floatdiv {
    display:none;
}

/* if screen size gets wider than 1024 */

@media screen and (min-width:1024px){
    #floatdiv {
        display:block;
    }
}

Note that in most modern browsers you can also run media queries in javascript using window.matchMedia

if(window.matchMedia("(min-width:1024px)").matches){
    console.log("window is greater than 1024px wide");
}