Add Custom button on Details view page under Cases Module

i want to add a Button in the cases Module where by click on that button need to post the to other application, by getting the phone number from the Accounts Module.

i am New to Suitecrm need this help so i can get some hands on development of SuiteCRM.

http://developer.sugarcrm.com/2011/01/12/howto-add-buttons-to-detail-and-edit-views/