var headline_box_selector = '#headline_box';
var headline_elapse_time = 5000;
var headline_count;
var headline_interval;
var old_headline = 0;
var current_headline=0;

function headline_startup() {
  headline_count = jQuery("div.headline").size();
  jQuery("div.headline:eq("+current_headline+")").css('top','0px');
  
  headline_interval = setInterval(headline_rotate,headline_elapse_time); //time in milliseconds
  jQuery(headline_box_selector).hover(function() {
    clearInterval(headline_interval);
  }, function() {
    headline_interval = setInterval(headline_rotate,headline_elapse_time); //time in milliseconds
    
  });
  headline_rotate();
}

function headline_rotate() {
  current_headline = (old_headline + 1) % headline_count; //remainder will always equal old_headline until it reaches headline_count - at which point it becomes zero. clock arithmetic
  var hiddenDimTop = -1 * parseInt(jQuery('#headline_box').css('height')) - 0 + 'px';
  //alert(hiddenDimTop);
  jQuery("div.headline:eq(" + old_headline + ")").animate({top: hiddenDimTop},"slow", function() {
    // jQuery(this).css('top','210px');
	// hidden dimension
	var hiddenDimBottom = parseInt(jQuery('#headline_box').css('height')) + 10 + 'px';
    jQuery(this).css('top', hiddenDimBottom);
    });
  jQuery("div.headline:eq(" + current_headline + ")").show().animate({top: 0},"slow");  
  old_headline = current_headline;
}