CRM 2011 - Query Number Cases Associated with the Customer (Contact record) from within a Case

Hi,

In the Case entity there is a Customer field that I can associate with an Account or a Contact.  Currently in my application this will always be a contact, and I would like to find a way to do a count on the number of Cases that this contact record is associated with, once selected.  What I need to do is then display this number on the case form that indicates how many cases the selected contact record has association with.

How can I do this in CRM 2011 using JavaScript?

Thanks!