The <vars> element, the <import> element, and the <screen> element are the three primary structural elements that occur inside the <HAScript> element (see Conceptual view of a macro script).

The <vars> element is optional. It contains <create> elements, each of which declares and initializes a variable (see Creating a new variable). The <vars> element must occur after the <import> element and before the first <screen> element.

To use variables, you must set the usevars element in <HAScript> to true.