Jquery Close Dialog Box

Question

I am wanting to add a close button to this dialog box. Can anyone tell me how to add this into my script?

var IE = (navigator.userAgent.indexOf("MSIE")>=0) ? true : false;

if(IE){

$(function(){

    $("<div>")
        .css({
            'position': 'absolute',
            'top': '0px',
            'left': '0px',
            backgroundColor: 'black',
            'opacity': '0.75',
            'width': '100%',
            'height': $(window).height(),
            zIndex: 5000
        })
        .appendTo("body");

    $("<div><img src='no-ie.png' alt='' style='float: left;'/><p><br /><strong>Sorry! This website doesn't support Internet Explorer.</strong><br /><br />If you'd like to read our content please upgrade your browser to a <a href='http://dpDesignz.webs.com/Suggested.html'&gt;Suggested Browser</a> to see this site.<br>Sorry for any inconvenience.</p>")
        .css({
            backgroundColor: 'white',
            'top': '50%',
            'left': '50%',
            marginLeft: -210,
            marginTop: -100,
            width: 410,
            paddingRight: 10,
            height: 200,
            'position': 'absolute',
            zIndex: 6000
        })
        .appendTo("body");
});     

}