The visibility of function can be applied to any object. The value returned by ESL is the boolean (true or false) associated with the visibility of the specified object. If the object is visible, the value true is returned; if it is invisible, the value false is returned. For example, the following code checks the visibility of an object to determine if the application is in the proper state:

response to GoButton

    if (visibility of PleaseWait) then

        action MustWait

    else

        action GoAhead

    end if