Right click Web Content -> New File -> name it javascript.js , add content below:
function setFocus()
{
var temp = document.getElementById( 'userName' );
temp.focus();
//document.forms[ 'login' ].elements[ 'userName' ].focus();
}
Modify the Login.jsp to include the following:
<body>
<script type='text/javascript' src="/ProjectName/javascript.js"></script>
<script type='text/javascript'>
setFocus();
</script>