title: Animation for a period
body: <p>I Asked this question before yesterday but it was closed because -maybe- of my bad english . so i will try to explain the best that I can . I have a div with background image , the png background is a set of images (contain many images and by changing css background position I can choose which image to appear in the div - I think it's a popular usage) .
  The problem is that I want to do an animation to do this:</p>
  
  <pre><code>$('div').css('background', "url('back.png') 0 -750px");
  </code></pre>
  
  <p>then :</p>
  
  <pre><code>$('div').css('background', "url('back.png') 0 -100px");
  </code></pre>
  
  <p>that's moving background up and down ,I want to do that for 4 sec ,I hope you understand 
  I tried delay(); setTimeout(); but they keep doing that forever !!</p>
  
  <p><em><strong>Update:</em></strong>  to explain more imagine a Gif image that flash for 4sec then stop !!</p>