(1) var DLs = top.$ ("#leftFrame"). Contents (). Find ("DL");
Top is an instance of the window class that represents the top-level form
All jquery objects can be viewed as attributes of the Windsow object.
Because a variable is defined in JS, such as var AVar = 1, it is equivalent to adding a property to the Window object.
The object that you just defined can be accessed through Windows.avar.
top.$ ("#leftFrame") used to find an IFRAME with ID leftframe in the top-level form.
$ ("#leftFrame"). Contents () is all elements of an IFRAME with ID leftframe in the top-level form
(2) top.$ ("#subNav a"). Get (INDEX_DL). Click ();
By (1) top.$ ("#subNav a") can get the elements of the top-level page
Note: Native JS code (the page in the IFRAME gets the other IFRAME page elements)
top.frames[' mainFrame '].document.getelementbyid ("AID"). Value
jquery frame pages manipulate elements in the top-level form, or elements in other frames pages