// JavaScript Document
var val=null;
var num='50';
var cpt=0;
var maxScroll=null;
var conteneurHeight=null;

$('div.scroll').removeClass('scroll').addClass('no-overflow').append('<span id="arrowUp" class="arrowUp"></span><span id="arrowDown" class="arrowDown"></div>').children('span.arrowDown').click( function(){
  conteneurHeight=$('div.no-overflow').css('height').replace('px', '')-50;
  maxScroll = $('div#scrollContent').css('height').replace('px', '')-conteneurHeight;
  if(cpt==0){
    val = num;
  }else{ 
    val = num*(cpt+1);
  }
  if(val<maxScroll){
    $('div#scrollContent').animate({
      marginTop: '-'+val
    }, 'fast');
    cpt++;
  }
}).parent().children('span.arrowUp').click( function(){
  if(cpt>-1){
    val = val-num;
    $('div#scrollContent').animate({
      marginTop: '-'+val
    }, 'fast');
    cpt--;
  }
});