Use context to define values of variables. If you want to learn how to use scripts to control values of variables I suggest you read this guide .

1. Under the tab Movie select Edit variables. Click the Add button and enter the name of your variable. Here you specify names of variables to be used in scrips etc. Variables defined here are part of this movie’s context only, they are only visible to scenes and objects in this movie.  

2. Under the tab Movie select Edit contexts. Add a new context and write a name for it. In the Edit context you should see your variables. To edit a variable, select a variables row and press F2 or click in the Value column. You could also select the row and then click the little symbol with three dots to open the text editor. Then click the Ok button. 

3. Connect variables to an object. Edit an object and under the tab Data click the button Connect Data. Select Varable and your variables should appear in a dropdown menu. Select the desired variable and click OK

4. Preview current scene and select which context should set the variables. Your movie should now be playing with the values from the variables.