Problem : Jquery slider working with asp datalist

Problem : Jquery slider working with asp datalist

Hi every body!
I need a slider in my website, that's gonna slide some essays reading from database.no matter if slides or fades(even better).
you know html code of asp datalist is like this:

<span id="MyDatalist">
      <span> ... </span>
      <span> ... </span>
      <span> ... </span> </span> or a table with id="MyDatalist" .
i tried that using fadeIn-fadeOut & show-hide . but since I'm a begginer in Jquery, I failed! like this:

var i=1
$("NextButton").click(function(){
if(i==1){
      $(span:first).fadeOut(500,function(){});
      $(span:second).fadeIn(500,function(){});}// end of if
}
else if(i==2){
      $(span:second).fadeOut(500,function(){});
      $(span:first).fadeIn(500,function(){});
      i=1}//end of else
});//end of click function

that was for two spans & works link this: hides the first, shows the second & again shows the first.and worse for more spans.
please help me.