question - .focus() not producing a dotted loutline

by spiderplant0

HTML

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" >
<title>Untitled Page</title>
<style>
  a:focus{
    background: yellow;
}
</style>
<script src="http://ajax.googleapis.com/ajax/libs/jquery/1.9.1/jquery.min.js"></script>

<script type = "text/javascript" >

$(document).ready(function(){
    $("#control1").click(function(){
        $("#link1").focus();
    });
});
</script>
</head>
<!-- <body onload="changeHashOnLoad(); "> -->
<body>
<div id="results"></div>
<a href="#" id="link1">link1</a>
<button id="control1">click</button>
 </body>
</html>