elements to the middle of web page code example

Example 1: how to make web page center

#page-wrap {
     width: 800px;
     margin: 0 auto;
}

Example 2: align centre

.headerTwoDiv{
			margin:1% auto;
			margin-right: auto; margin-left: auto; width: 21%; 
			padding-top: 11px;
		}