var tscr = $('#content-inner').css('top');
    var spd = 4;
    var timer;
    var dht = 0;
    
    function scrollDown(){
      tscr = $('#content-inner').css('top');
      tscr = tscr.substring(0,tscr.length-2);
      tscr = tscr - spd;
      $('#content-inner').css('top',tscr+'px');
      if(tscr>(-1*dht)){
        timer = setTimeout("scrollDown()", 10);
      }else{
        clearTimeout(timer);
      }
    }
    function scrollUp(){
      tscr = $('#content-inner').css('top');
      tscr = tscr.substring(0,tscr.length-2);
      tscr = 1 * tscr + spd;
      $('#content-inner').css('top',tscr+'px');
      if(tscr<0){
        timer = setTimeout("scrollUp()", 10);
      }else{
        clearTimeout(timer);
      }
    }
    
    $(function(){
      dht = $('#content-inner').height() - 360;

      $('.sdn').hover(function(){
        timer = setTimeout("scrollDown()", spd/10);
      },function(){
        clearTimeout(timer);
      });
      
      $('.sup').hover(function(){
        timer = setTimeout("scrollUp()", spd/10);
      },function(){
        clearTimeout(timer);
      });
      
    });