No Calendar Pop-up Showing..

Hi

When I click the field as per the instructions, no calendar pops up. I’ve created a [date yourdate] using the Generate Tag function, it displays a field in my contact form, but when I click it no calendar pops up.

I cannot update my wordpress coz i am not the one who created the site..
maybe they change some code that i did not know..so if i update wp the site will not work properly..

Can anyone help me with this plugins..I only need to show the calendar and and they can select date from the calendar..

Thanks.

http://wordpress.org/plugins/contact-form-7-datepicker/