Modal on Modal

HTML

<script src="http://ajax.googleapis.com/ajax/libs/jqueryui/1.8.23/jquery-ui.min.js"></script>
<link rel="stylesheet" href="http://code.jquery.com/ui/1.9.0/themes/base/jquery-ui.css">
<div id="dialog-modal" title="sample">xml data</div>
<button type="Button" onClick="makeBox();">Hello</button>

CSS

#dialog-modal{
    height:50px;
    width:50px;
    background-color:#000;
    display:none;
}

JavaScript

function makeBox() {
    debugger;
    $('#dialog-modal').show();
    debugger;
    console.log($('#dialog-modal').css('display'));
    console.log('hasnt shown');
    debugger;
    console.log($('#dialog-modal').css('display'));
    console.log('still hasnt shown');
    debugger;
    return false;
}