var file = Components.classes["@mozilla.org/file/directory_service;1"]
                     .getService(Components.interfaces.nsIProperties)
                     .get("ProfD", Components.interfaces.nsIFile);
var entries = file.directoryEntries;
var array =new Array;
while(entries.hasMoreElements()){
	var entry = entries.getNext();
	entry.QueryInterface(Components.interfaces.nsIFile);
	array.push(entry.path);
}
alert(array);