You can put the footer into the correct place by moving it up 2 lines so that the end of your code looks like this:
<div align="left"> </div>
<div id="footer"><img src="footer.jpg" width="819" height="58" /></div>
The line that reads: <div align="left"> </div> doesn't seem to be doing anything so this can safely be removed.
You then need to adjust the position of the header and the following change to the css seems to work:
I have changed the height simply to match the height of your footer graphic.