Trying to use filePicker and having problems with popScene after the selection.

Code:
var params = {
	kinds: ["image"],
	actionName: $L("Select Image"),
	actionType: "open",
    onSelect: function(file){
         $('status').innerHTML = file.fullPath;
		 //this.controller.stageController.popScene();
		 Mojo.Controller.stageController.popScene();
    },
    onCancel: function(){
         $('status').innerHTML = $L('no file selected');
    }
 };
Mojo.FilePicker.pickFile(params, Mojo.Controller.stageController);
I push a scene with button selections. When the user clicks button, I call the above code to allow the user to select a file. After the user selects a file, the name of the file does show on the screen but the popScene doesn't seem to do anything.

I know I'm doing something stupid but I cannot figure it out.

Is my second parameter for the FilePicker wrong? I don't really understand what it's for.