8.5

The Expression Editor dialog box enables you to create and validate expressions.
You can build several kinds of expressions. The following are the most common types of
expressions:
• Calling a function on an interactive object: Here, you're basically telling an object to do
something. For example, to make a hidden object visible, you can call the SetVisible
function on that object: MyBox.SetVisible(true)
• Assigning a value to a variable: Here, you're changing a variable's value. For example, you
might assign the contents of a Text Box object to a variable named "UserName":
UserName = MyTextBox.GetText()
Calling a function on an interactive object
To build an expression that calls a function on an interactive object:
1
To operate on an interactive object that is already present in the layout, select that object's
name in the Objects list. Use the drop-down menu at the top of the list to narrow the list
of objects by type.
2
Double-click the object's name to add it to the editing area.
3
To see the list of functions that can be called on this particular type of object, choose that
object type from the Functions drop-down menu. For example, if you are working with
an Animation object, choose Animation.
4
Scroll through the Functions list until you find the function you want. To determine what
a function does, click its name and look at the description that displays at the bottom of
the dialog box. For this type of expression, you usually need a function that does not
return a value, so look for function descriptions that do not start with the word "Get." For
example, to start an Animation object playing, choose Animation.Play().
5
Double-click the function name to add it to the editing area.
A GUIDE TO QUARKXPRESS 8.5: PLUS EDITION | 321
INTERACTIVE LAYOUTS