.hitalkform{
width: 950px;
height: 500px;
position: absolute;
top: 0px;
left: 0px;
background-color: white;
z-index:2;
position: fixed;
}
.zhezhao{
	position: fixed; 
	top: 0%; 
	left: 0%;
	width: 100%;
	height: 100%;
	background-color: black; 
	z-index: 1; 
	opacity: 0.7;
	filter: progid:DXImageTransform.Microsoft.Alpha(opacity=70);
}