# Checking for loaded data

Each action and method that loads data into a movie (except `XMLSocket.send`) is asynchronous: the results of the action are returned at an indeterminate time.

Before you can use loaded data in a movie, you must check to see if it has been loaded. For example, you can't load variables and manipulate their values in the same script. In the following script, you can't use the variable `lastFrameVisited` until you're sure the variable has loaded from the file `myData.txt`:

    loadVariables("myData.txt", 0);
    gotoAndPlay(lastFrameVisited);

Each action and method has a specific technique you can use to check data it has loaded. If you use the `loadVariables` or `loadMovie` action you can load information into a movie clip target and use the `data` event of the `onClipEvent` action to execute a script. If you use the `loadVariables` action to load the data, the `onClipEvent(data)` action executes when the last variable is loaded. If you use the `loadMovie` action to load the data, the `onClipEvent(data)` action executes each time a fragment of the movie is streamed into the Flash Player.

For example, the following button action loads the variables from the file `myData.txt` into the movie clip `loadTargetMC`:

    on(release){
    	loadVariables("myData.txt", _root.loadTargetMC);
    }

An action assigned to the `loadTargetMC` instance uses the variable `lastFrameVisited`, which is loaded from the file `myData.txt`. The following action will execute only after all the variables, including `lastFrameVisited`, are loaded:

    onClipEvent(data) {
    	goToAndPlay(lastFrameVisited);
    }

If you use the `XML.load` and `XMLSocket.connect` methods, you can define a handler that will process the data when it arrives. This handler is a property of the XML or XMLSocket object to which you assign a function you have defined. The handlers are called automatically when the information is received. For the XML object, use `XML.onLoad`. For the XMLSocket object, use `XMLSocket.onConnect`.

For more information, see Using the XML object and Using the XMLSocket object.