popupLogin example - JQM 1.3.0 - popup in popup - cut and paste mistake?

popupLogin example - JQM 1.3.0 - popup in popup - cut and paste mistake?

Below is the start of the code sample for the popupLogin example. Note that the popup is inside of a popup. The outer popup has an id of popupMenu so I am thinking there was a cut and paste mistake when the example was created. The example works because the definition of popupMenu is present. But, I can't see why there would be a need for the popup with an id of popupMenu wrapped around the popup with an id of popupLogin.

< a href = "#popupLogin" data-rel = "popup" data-position-to = "window" data-role = "button" data-inline = "true" data-icon = "check" data-theme = "a" data-transition = "pop" >Sign in</ a >
< div data-role = "popup" id = "popupMenu" data-theme = "a" >
     < div data-role = "popup" id = "popupLogin" data-theme = "a" class = "ui-corner-all" >