Submit button's value disappears onClick

I have a simple form that takes in a user's e-mail address (the form appears when "E-mail" link clicked on). Everything appear开发者_高级运维s to function correctly, except that the value for the submit button disappears onClick or onSubmit. I can't seem to track down the issue. Please reference here. This issue only appears to affect IE. I'd prefer not to show PHP processing - but if necessary I'll show what I can. Basically, just wondering if anyone can spot any syntax errors that might be causing this, or if anyone has a solution.

Form:

<div id="formContainer">
    <form action="http://www.example.com/catalog/scripts/email.php" method="post" id="contactForm">
        <input type="text" name="email" value="E-mail Address" id="email" style="padding-left:5px; font:bold 11px Arial;"/> 
        <input type="text" name="last" value="" id="last" />
        <input type="hidden" name="id" value="'.$_GET['id'].'">
        <input type="submit" value="Submit" id="contactSubmit"/>
    </form>
</div>

JS:

<script>
    $(document).ready(function() {var options = {target: '#alert'};
    $('#contactForm').ajaxForm(options); });
    $.fn.clearForm = function() {
        return this.each(function() {
            var type = this.type, tag = this.tagName.toLowerCase();
            if (tag == 'form')
                return $(':input',this).clearForm();
            if (type == 'text' || type == 'password' || tag == 'textarea')
                this.value = '';
            else if (type == 'checkbox' || type == 'radio')
                this.checked = false;
            else if (tag == 'select')
                this.selectedIndex = -1;
        });
    };
</script>