NotesCount is a client side JScript customization, which enables CRM useres to recognize the amount of attached notes or attachments to any CRM record (e.g. contact, account, case, …) within the tab on top of the main form of the record.
Intention
NotesCount is intended to improve the UX of all Microsoft Dynamics CRM 4.0 users. By showing the amount of attached notes or files referenced to CRM records without opening the notes tab it will reduce the risk to miss important information.

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More info & Download: http://notescount.codeplex.com/