#chatBox {
    padding-top: 20px;
    padding-bottom: 20px;
    height: 300px;
 	overflow: scroll;
}

.contentBox {
  	border: 1px solid black;
  	padding-left: 20px;
  	padding-right: 20px;
  	background-color: rgb(255, 255, 255);
}

.mainScreen {
  	position: absolute;
  	top: 20px;
  	left: 20px;
  	border: 1px solid black;
}

#contents {
  	position: relative;
  	border: 1px solid blue;
}