When the mouse is moved flashing when switching background problem

When the page is first loaded, the background of the need to switch into the mouse has not been loaded before, this picture is not local, it is time to switch back to the flickering occurs, we can put this figure down in one place but do not let it show, background image so that when we finished the first time the page is loaded will need to switch the load over, switch the background image will no longer flicker when we move the mouse again, but this way and not suitable for all situations, if we need to switch the picture too much, so will the pressure when the page loads too large a burden browser, only need to set a few pictures when this method can be used.