To add a global variable to a codeunit, use the following procedure.
To add a global variable
- Open the C/AL Editor, choose View, and then choose C/AL Globals.  Note Note- For more information about how to open the C/AL Editor, see How to: Modify an Existing Codeunit. 
- In the C/AL Globals window, choose the Variables tab. 
- Enter a name and select a data type. - If the data type that you select corresponds to an application object, you must also select a subtype, that is, the name of a specific object in the database. - If you select OCX, Automation, or DotNet, then you must add a subtype. For more information, see the following topics: - Extending Microsoft Dynamics NAV Using COM
- Extending Microsoft Dynamics NAV Using Microsoft .NET Framework Interoperability
 - If you select text or code, you must define a length for the variable. The default length is 10 characters for code and 30 characters for text. 
- Extending Microsoft Dynamics NAV Using COM





