Firefox does not support the innerText property.
<html>
<head>
<title>InnerText Example</title>
<script type="text/javascript">
function useInnerText() {
var oDiv = document.getElementById("div1");
oDiv.innerText = "<b>Hello</b> world";
}
</script>
</head>
<body>
<div id="div1">This is my original text</div>
<input type="button" value="Use InnerText" onclick="useInnerText()" />
</body>
</html>