This property is useful when customizing the JsChartViewer.serverErrorMsg. It provides the code required to close the message window. It is also used as the close window button for partial update notification messages.
You may customize the "OK" button by creating it in HTML, using "%closeScript" as the place holder for the Javascript that closes the window.
As an example, the default "OK" button is:
<center>[<a href="javascript:%closeScript"> OK </a>]</center>
Note: This is a static property (class property). It should be accessed as JsChartViewer.okButton, not objName.okButton.