Stuff

<html>
    <head>
        <script>
            function toggle() {
                toggleEle(document.getElementById("aa"));
                toggleEle(document.getElementById("bb"));

                return false;
            }

            function toggleEle(ele) {
                ele.readOnly = !ele.readOnly;
                ele.style.backgroundColor = ele.readOnly ? "#eee" : "#fff";

                var val = ele.readOnly ? "readonly" : "editable";
                ele.value = val + ", set onclick";
            }

        </script>
    </head>
    <body>
        <p>
            <textarea readonly="true" id="aa">readonly</textarea>
            <textarea id="bb">editable</textarea>
        </p>
        <p>
            <a href="" onclick="return toggle();">Toggle</a>
        </p>
    </body>
</html>