body { padding: 0; margin: 0; }  #overlay{ width: 100%; height: 100%; position: fixed; top: 0; left: 0; background-color: rgba(119,136,153,0.7); z-index:99999;}  #box_frame{ width: 100%; position: fixed; top: 5%;border:0px dotted green;}   #box{width: 800px; padding: 10px; background-color: #d6d6d6; border: 0px dotted gray; font-size: 15px; margin: auto; text-align:center;height:520px;overflow-y:hidden;overflow-x:hidden;position:relative;} #clsBx { width:100px;border:0px solid yellow;text-align:right;position:absolute;top:10;right:16; }