[jQuery] Validation Plugin - How to Validate input="file"

[jQuery] Validation Plugin - How to Validate input="file"


I'm trying to validate that someone has selected a file for upload
before submitting a form. I set the required class on the input
element, but it's not being validated. The regular text input is
validated, however.
<form:form id="pictureform" commandName="pictureCommand"
    action="${actionURL}" method="post" enctype="multipart/form-data"
    cssClass="update">
    <div>
        <label for="title">
            Title:
        </label>
        <form:input path="title" cssClass="required" />
    </div>
    <div>
        <label for="description">
            Description:
        </label>
        <form:textarea path="description" />
    </div>
    <label for="image">
        Select File:
    </label>
    <input type="file" name="image" cssClass="required" />
    <input type="submit" value="Add" />
</form:form>