JQuery validate.addMethod not working to display error for a blank HTML input
===

> The required calendar input works as expected. After submit, validate displays error message if a
> valid date not selected from datepicker, but blank text input won't work by similiar manner.
 
    <!DOCTYPE HTML>
    <html lang="en-US">
    <head><title>
    </title>
    <script type='text/javascript' src='http://code.jquery.com/jquery-1.5.1.min.js'></script>
    <script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jqueryui/1.8.5/jquery-ui.js"></script>
    <script type="text/javascript" src="http://ajax.microsoft.com/ajax/jquery.validate/1.5.5/jquery.validate.min.js"></script> 
    <script type="text/javascript" src="http://jquery-multifile-plugin.googlecode.com/svn-history/r16/trunk/jquery.MetaData.js"></script> 
    <link rel="stylesheet" type="text/css" href="http://ajax.googleapis.com/ajax/libs/jqueryui/1.8.5/themes/base/jquery-ui.css"/>

    <script type="text/javascript">
        $(document).ready(function () {
            $.validator.addMethod("regexp", function (value, element, param) {
                return this.optional(element) || !param.test(value);
            });
            $("#form1").validate({
                rules: {
                    debug: true, //prevent submission for testing
                    textbox: {
                        required: true,
                        regexp: /['"]/
                    },
                    methods: {
                        required: "Should not be blank",
                        regexp: "Single quotes and double quotes not allowed"
                    }
                }
            });
            $(".date").datepicker({
                changeYear: true,
                dateFormat: 'dd/mm/yy',
                minDate: new Date('1990/01/01'),
                maxDate: '30Y'
            });
        }); 
    </script>
    </head>
    <body>
            <form method="post" action="WebForm1.aspx" id="form1">
                Select Date2:<font color="red">* </font><input id="datetext" class="date {required:true,messages:{required:'Required:Need to select a date.'}}" readonly="true" /><br />
                Text:<font color="red">* </font><input id="Text1" class="lvl"  /><br />
               <input type="submit" value="Submit"/>
            </form>
    </body>
    </html>