# Testing Databoxes & Expressions Expressions can be created against all types of Databox except Company Data (aka Fixed Text). Wherever you create Expressions, a Test facility is provided. In essence, it will allow you to evaluate what happens when certain data is encountered by the Databox. When you click **Test** (in the Editing pane, not the main menu) a popup window will appear where you can supply a value for the Databox by entering a value. Then click **Evaluate**. Any errors will be reported but, if all is well, you will see the results of the Expressions:

### Here's an idea... You might find that it's a useful idea to have a 'scratch' Databox whose only purpose is to house a number of example Expressions which you can use to test and confirm that the (sometimes esoteric!) formatting is correct. Here's such a random selection:

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