CODE EXAMPLE FOR CSS

fixed image background css

#hero1{
 background:url(https://4.bp.blogspot.com/_AQ0vcRxFu0A/S9shDGGyMTI/AAAAAAAAAYk/kn3WTkY2LoQ/s1600/IMG_0714.JPG);
  background-size:cover;
  background-position:center center;
  background-attachment:fixed;