jquery alert issue difficult

<script src="jquery.tagcanvas.js" type="text/javascript"></script>
    <script type="text/javascript">
        //alert("aa");
        $(document).ready(function() {
            alert('aa');          <<- THIS IS NOT GETTING PRINTED ON RUNTIME. WHY ??
            if (!$('#myCanvas').tagcanvas({
                textColour: '#FFFFFF',
                outlineColour: '#ff00ff',
                reverse: true,
                depth: 0.8,
                maxSpeed: 0.05
            }, 'tags')) {
              $('#myCanvasContainer').hide();
            }
        });
    </script>