9.3

Table Of Contents
The Number object is simply a library of math functions, rather than an interactive object.
This expression tells the Number object's Sqrt function to calculate the square root of two
and store the result into the variable named "MyVariable."
To refer to an object in an expression, that object must follow certain naming conventions.
It may not begin with a number, and it may not contain any symbols other than a dollar
sign ($) or an underscore (_). If it contains spaces, you can substitute underscores for them
when you refer to it in an expression.
Using the Expression Editor dialog box
The Expression Editor button displays the Expression Editor dialog box. You can use
this dialog box to create expressions in two ways:
If you are new to expressions, you can build them by double-clicking items in the lists in
the top half of the dialog box in the proper order.
If you are familiar with expression syntax, you can enter your expressions directly into
the large editing field.
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()
A GUIDE TO QUARKXPRESS 9.3 - PLUS EDITION | 359
INTERACTIVE LAYOUTS