var _allTextContainers = app.activeDocument.stories.everyItem().textContainers; 
 
for(var i=0; i<_allTextContainers.length; i++) { 
  for(var j=0; j<_allTextContainers[i].length; j++) { 
    if(_allTextContainers[i][j] instanceof TextFrame &&  
       _allTextContainers[i][j].parentPage == null &&  
       _allTextContainers[i][j].label == "myTextFrame") { 
         alert(_allTextContainers[i][j].contents) 
    } 
  }  
}