jQuery in JavaScript does not work
===

the following Code works expect for the jQuery part.
The code makes 6 dots black and stops the interval, but does not fadeIn the div with the id "cs".

Whats my mistake?

    <script src="http://ajax.googleapis.com/ajax/libs/jquery/1.5/jquery.min.js"></script>
	<script type="text/javascript">
	

    (function() {
        var delayInSeconds = 0.5;                           
        var num = 0;
        var changeDot = function() {
			document.getElementById('dot' + num).style.backgroundColor = "#000";
			num++;
			if(num == 6)
			{
				$('#cs').fadeIn('slow');
				window.clearInterval(int);
			}
        };
       var int = window.setInterval(changeDot, delayInSeconds * 1000);
    })();
    </script>