div1 is in the centre of screen and I want div2 in the centre of div1
<div id="div1">
<div id="div2"></div>
</div>
css:
#div1{
top:0;
left:0;
right:0;
bottom:0;
margin:auto;
position:fixed;
width:595px;
height:842px;
background-color:#F0F0F0;
}
#div2{
}