Note that dimension value codes are always company-defined and company-named. To see the dimension value codes for your company, click General Ledger, Setup, Dimensions, Dimensions. Select the relevant dimension and click Dimension, Dimension Values.
You can enter dimension values in sales and purchase documents and in all journals. The following procedure is for entering dimension values on a sales document:
Open the 
Sales Order
window.
Fill in the fields in both the header and on the entry line. For Help about a specific field, click the field and press F1.
Click Line, Dimensions.
On the new line, click the AssistButton 
and select the relevant
dimension.
To post the entry, click Posting, Post.
The Document Dimension window may already display some dimensions and their dimension values. These are the default dimensions related to the account types that you have entered in the header and on the entry line. You can choose to enter another dimension value than the proposed default, depending on which option you have set up in the Value Posting field for the default dimension.
Note that the same window for journals is called the Journal Line Dimension window.
You can enter up to eight dimensions values directly on the entry line. To insert the available dimensions, use the Show Column function.
Correcting Dimension Value Codes on Item Ledger Entries for Purchase
Correcting Dimension Value Codes on Item Ledger Entries for Sales
Correcting Dimension Value Codes on Ledger Entries