popup window working very well.
.backdrop appear half part 🙁
here is the css code
.backdrop
{
position:absolute;
top:0px;
left:0px;
width:100%;
height:100%;
background:#000;
opacity: .0;
filter:alpha(opacity=0);
z-index:50;
display:none;
}
image sample

You should be able to easily fix this by changing
positionfromabsolutetofixed.You could also give it a very large pixel value rather than 100% for the height and width if you don’t want to use
position: fixed;, ie.height: 99999px; width: 99999px;, but this can cause other issues that will have to be addressed (such as scrollbar issues).