Question

There is a syntax error in this function, but I am not clear what it is.
The username is stored on a cookie and retrieved by the server, if it exists.
When the page loads, if the username does not get populated, I want the focus on the username textbox.
Otherwise I want it on the password textbox;

<h2>Log On</h2>
<p>
    Please enter your username and password.
</p>
<% using (Html.BeginForm()) { %>
    <%: Html.ValidationSummary(true, "Login was unsuccessful. Please correct the errors and try again.") %>
    <div>
        <fieldset>
            <legend>Account Information</legend>

            <div class="editor-label">
                <%: Html.LabelFor(m => m.UserName) %>
            </div>
            <div class="editor-field">
                <%: Html.TextBoxFor(m => m.UserName) %>
                <%: Html.ValidationMessageFor(m => m.UserName) %>
            </div>

            <div class="editor-label">
                <%: Html.LabelFor(m => m.Password) %>
            </div>
            <div class="editor-field">
                <%: Html.PasswordFor(m => m.Password) %>
                <%: Html.ValidationMessageFor(m => m.Password) %>
            </div>

            <div class="editor-label">
                <%: Html.CheckBoxFor(m => m.RememberMe) %>
                <%: Html.LabelFor(m => m.RememberMe) %>
            </div>

            <p>
                <input type="submit" value="Log On" />
            </p>
        </fieldset>
    </div>
<% } %>
<script type="text/javascript" language="javascript">
    $(document).ready(function () {
        if (!$.trim($("#UserName")).length) { // zero-length string AFTER a trim 
            $("#UserName").focus();
            }
        else {
            $("#Password").focus();
        } 
    }); 
</script>

Answer 1

I found this did the trick;

        // Put cursor on the first empty textbox.
        $(document).ready(function () {
            $('form input[value=]:first').focus();
        });