Gets the list items being selected.
var value = SP.ListOperation.Selection.getSelectedItems();
The key/value collection that contains the list items being selected.
The key in the dictionary is the zero-based integer value. The value is an object that contains two attributes, id and fsObjType, where id is the ID of the list item, and fsObjType is the type of the item: 0 = list item or document, 1= folder.