How to search image (locator) using sikuli

Some time we are getting that image are not displayed on screen which is captured by sikuli at run time.

Such as we open a www.google.com on browser search a text like "testing" and click on searched button we observed that we need to scroll down to click on next button which is at footer. If I used direct sikuli click command to click on next button we will get exception because image not visible on page. I am using below approach to click on next button

I created below function to check image is present on screen or not :

         public boolean clipExist(Screen screen, String clip )
        {
               Match m = screen.exists(clip);
                if(m != null)
             {
                     return true;
               }
              else
              {
                 return false;
              }
          }

I created below code to scroll down and click on next button if exist:
   
       Screen screen = new Screen()
       screen.type(null, "Testing", 0);
        screen.click("images/GoogleSearchButton.png", 0);
        Thread.sleep(2000);
        while( ! clipExist(screen, "images/GoogleLink.png"))
        {
            screen.wheel(1 , 3);
            if(clipExist(screen, "images/Next.png"))
            {
                screen.click("images/Next.png", 0);
                break;
            }
        }