As you may know, Microsoft Dynamics CRM 2013 completely removed support for the Dynamics CRM 4.0 JavaScript object model. In fact, you will be unable to upgrade your organization to 2013 should 4.0 ...
There are LOTS of good resources for learning how to do Dynamics CRM form-scripting — i.e., placing JavaScript code behind the onLoad and onSave form events, and behind the onChange event of any field ...
As you may know, Microsoft Dynamics CRM 2013 completely removed support for the Dynamics CRM 4.0 JavaScript object model. In fact, you will be unable to upgrade your organization to 2013 should 4.0 ...