document.observe('dom:loaded', function() {   
	  if (screen.width <= 1024) {              
                document.body.style.backgroundImage="url('http://www.boo-tique.co.uk/skin/frontend/default/bootique/images/backgrounds/background_1024.jpg')";
          }
          else if ((screen.width > 1024) && (screen.width <= 1600))
          {              
                document.body.style.backgroundImage="url('http://www.boo-tique.co.uk/skin/frontend/default/bootique/images/backgrounds/background_1600.jpg')";
          }
          else if ((screen.width > 1600) && (screen.width <= 1920)) {                
                document.body.style.backgroundImage="url('http://www.boo-tique.co.uk/skin/frontend/default/bootique/images/backgrounds/background_1920.jpg')";
          };         
          
	  document.body.style.backgroundRepeat = "no-repeat";          
});