var blockIt='block';
    $(document).ready(function() {
       (function($){
			$.fn.positionCenter = function(options) {
            var pos = {
              sTop : function() {
                return window.pageYOffset || document.documentElement && document.documentElement.scrollTop ||  document.body.scrollTop;
              },
              wHeight : function() {
                return window.innerHeight || document.documentElement && document.documentElement.clientHeight || document.body.clientHeight;
              }
            };
            return this.each(function(index) {
              if (index == 0) {
                var $this = $(this);
                var elHeight = $this.outerHeight();
                var elTop = pos.sTop() + (pos.wHeight() / 2) - (elHeight / 2);
                $this.css({
                  position: 'absolute',
                  margin: '0',
                  top: elTop,
                  left: (($(window).width() - $this.outerWidth()) / 2) + 'px'
                });
              }
            });
          };
        })(jQuery);
      });
  
      $(document).ready(function() {
        $('<div/>')
          .attr('id','centeredMsg')
          .html('<h2 id=changingTxt>'+msg+'</h2>')
          .hide()
          .appendTo('body');
          
        $('button').click(function() {
          $('#centeredMsg').animate({opacity: 'toggle'}, 400).positionCenter();
          });
        
      });
    
function hideAlert(){
	document.getElementById("centeredMsg").style.display="none";
}