popup reposition?

popup reposition?

I am building a list dynamically How can i get the popup to reposition itself to the center of the screen after i have added or removed items from the list?

    $("#mylist").append('<li><a href="#">Number 1</a></li>');
    $("#mylist").append('<li><a href="#">Number 2</a></li>');
    $("#mylist").append('<li><a href="#">Number 3</a></li>');
    $("#mylist").append('<li><a href="#">Number 4</a></li>');
    $("#mylist").listview('refresh');

I have tried:
$( "#popupBasic2" ).popup( "close" );
$( "#popupBasic2" ).popup( "open" );

But that didn´t work. The popup closed but never opened again.