Add Variable: Click Add Variable to define the first variable that you want. Available only when no variables were previously added.
Add: Click Add to define another variable. Available only after at least one variable is added.
Variables: Displays each variable that has been added. Click a variable in the list to view its Name and Value properties.
Name: Displays the name of the variable that is currently selected in the Variables list. You can enter a new name in the text box. Alternatively, you can add a variable to specify the name that you want.
Value: Specifies the value for the variable that is currently selected in the Variables list. You can enter a new value in the text box. Alternatively, you can add a variable to specify the value that you want or add a special character to the value that you enter.
Import: Opens the Open File dialog so that you can browse to and open a file that contains the values that you want to be assigned to the variable. When you open the file, its contents are imported into the Value field.
Export: Opens the Save File dialog so that you can save the contents of the Value field as an external file. You can save the value as a new file or replace the contents of an existing file.
Edit variable value 
: Opens the Value for dialog, where you can edit the value of the variable.