I've tried using other code suggestions to change the focus to another field:
document.getElementById('{!$Component.fOpportunity}').focus();
and changing the focus on load:
<script>function setFocusOnLoad() {}</script>
But neither of them seem to work. I notice the focus is on the field I want it on for a brief second but then changes over to the date field. Is there a specific place I should put this code to change the focus?