Table header freez

Sir I have this example

http://brentmuir.com/projects/freezeheader/demo.html

Table header freez when header row touch screen top.

Now I have these code to freez table header

	
	
	
	Untitled Document
	
	
	body{
		padding:30px;
	}
	.box1{
	margin:0 auto;
	width:60%;
	padding:20px;
	border:1px solid blue;
	text-align:center;
}
table
{
	width:50%;
	text-align:center;
	margin:0 auto;
}
th {
	width:50%;
	border:1px solid red;
	background-color:gold;
	color:#4F38C0;
	line-height:25px;
	font-weight:bolder;
	font-size:16px;
}
tr {

	border:1px solid blue;
}
td {
	border:1px solid blue;
}

	
	
	<div class="box1">
	 This is Table header freezing example
	
	
	
	Header 1
	Header 2
	
	
	OneTow
	OneTow
	OneTow
	OneTow
	OneTow
	OneTow
	OneTow
	OneTow
	OneTow
	OneTow
	OneTow
	OneTow
	OneTow
	OneTow
	OneTow
	OneTow
	OneTow
	OneTow
	OneTow
	OneTow
	OneTow
	OneTow
	OneTow
	OneTow
	OneTow
	OneTow
	OneTow
	OneTow
	OneTow
	OneTow
	OneTow
	OneTow
	OneTow
	OneTow
	OneTow
	OneTow
	OneTow
	OneTow
	OneTow
	OneTow
	OneTow
	OneTow
	OneTow
	OneTow
	OneTow
	OneTow
	OneTow
	OneTow
	OneTow
	OneTow
	OneTow
	OneTow
	OneTow
	OneTow
	OneTow
	OneTow
	OneTow
	OneTow
	OneTow
	OneTow
	OneTow
	OneTow
		
	</div>      
	
	

How and where to add codes to make my table header freez like shown in the link of this thread.

Please help