var scrollDist = 0;
var scrollInc = 155;
var sliderHeight = 0;
var viewerHeight = 0;
function scrollUp()
{
  scrollDist -= scrollInc;
  var targetMargin = scrollDist + "px";
	$("#eventSlider").animate({marginTop:targetMargin},{duration: 500});
}
function requestUpScroll()
{
  if (sliderHeight + scrollDist > viewerHeight)
  {
    scrollUp();
  }
  return false;
}
function scrollDown()
{
  scrollDist += scrollInc;
  var targetMargin = scrollDist + "px";
  $("#eventSlider").animate({marginTop:targetMargin},{duration:500});
}
function requestDownScroll()
{
  if (scrollDist < 0)
  {
    scrollDown();
  }
  return false;
}
function wireUpButtons()
{
	sliderHeight = $("#eventSlider").height();
	viewerHeight = $("#eventFrame").height();
	if (sliderHeight > viewerHeight)
	{
    $("#arrows").show();
  }
	$("#uparrow a").click(requestDownScroll);
	$("#downarrow a").click(requestUpScroll);
}
$(document).ready(wireUpButtons);