Hi, amazingly it works! Really thanks a lot for your help...
I got one more question, do you have any idea how I can validate both the datefield to ensure it is a valid Datetime in a specific format? Because even with the datepicker, user can input any string/numbers in the textfield and click submit.. so I want to validate those manually entered value to ensure it is a DateTime which match the format of my datepicker's Date declared as:

$('#expirydate').datepicker({
            constrainInput: true,
            minDate: 0,
            dateFormat: 'D, dd M yy'
        });

And one of the datetime form field with the format:

<div class="editor-label">
        Expiry Date
    </div>
    <div class="editor-field">
        @Html.TextBox("ExpiryDate", String.Format("{0:ddd, d MMM yyyy}", DateTime.Now), new { id = "expirydate" })
        @Html.ValidationMessageFor(model => model.ExpiryDate)
    </div>

Really thanks a lot for your help!