[jQuery] How to move the DIV?

[ace jquery]

Hi there,

I am trying to move the div object, but it seems doesn't work.  any
ideas? Thanks

<script language="javascript">


        $(document).ready(function () {

                $("<div/>" )
                        .attr( "id", "myDiv")

                        .addClass( "header" )

                        .html( "hello world")

                        .appendTo( $( "body" ) );

                        
                $( "myDiv" ).css('left', '150px');

        });
</script>