让span有固定宽度

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" >
<head><title>Test Span</title>
<style type="text/css">
span { background-color:#ffcc00; display:-moz-inline-box; display:inline-block; width:150px;}
</style>
</head>
<body>
fixed <span>width</span> span
</body></html>