You can determine whether an object is visible or
To hide/unhide an object:
Double click the object you would
like to hide.
Select the Appearance tab.
Select the Visibility tab (to the right of the dialog).
Click the Wizard button to the right of the Hidden when field.
Select either Insert Tag or Insert Function
depending on which you would like to relate to your object.
Enter an expressionA statement (or group of statements) that returns
a value. An expression can be a single variable, a mathematical
formula, or a function. in the Hidden when field. When this expression is true your
object will be hidden.