Create Panel in HTML

<script type="text/javascript">
function openDialog(contents)
{
    document.getElementById("glass").style.display='block';
    document.getElementById("panel").style.display='block';
}

function closeDialog()
{
    document.getElementById("glass").style.display='none';
    document.getElementById("panel").style.display='none';
}

</script>

<input type="button" value="Open Dialog" onclick="openDialog()" />

<div id="glass" style="position: absolute; left: 0px; top: 0px; visibility: visible; width: 100%; height: 100%; display: block; background-color: black; opacity: 0.3; display: none;"></div>
<div id="panel" style="position: absolute; left: 10%; top: 10%; overflow: visible; border: 3px solid #BABBBC; background:  #F3EBD6; width: 80%; height: 80%; padding: 5px; display: none;">
    <input type="button" onclick="closeDialog()" value="Close" />
</div>