make it middle css code example

Example 1: how to center an image element inside a block in css

img { display:block;
      margin-left: auto;
      margin-right:auto;
      }

Example 2: css position element in the middle of a header

P.blocktext {
    margin-left: auto;
    margin-right: auto;
    width: 200px;/*usually works best with a fixed width*/
}