Working with Movie Clips and Buttons > Using actions and methods to control movie clips > Changing movie clip position and appearance |  |

Changing movie clip position and appearance

To change the properties of a movie clip as it plays, write a statement that assigns a value to a property or use the `setProperty` action. For example, the following code sets the rotation of instance `mc` to 45:

    mc._rotation = 45;

This is equivalent to the following code, which uses the `setProperty` action:

    setProperty("mc", _rotation, 45);

Some properties, called read-only properties, have values that you can read but not set. (These properties are specified as read-only in their ActionScript Dictionary entries.) The following are read-only properties: `_currentframe`, `_droptarget`, `_framesloaded`, `_parent`, `_target`, `_totalframes`, `_url`, `_xmouse`, and `_ymouse`.

You can write statements to set any property that is not read-only. The following statement sets the `_alpha` property of the movie clip instance `wheel`, which is a child of the `car` instance:

    car.wheel._alpha = 50;

In addition, you can write statements that get the value of a movie clip property. For example, the following statement gets the value of the `_xmouse` property on the current level's Timeline and sets the `_x` property of the `customCursor` instance to that value:

    onClipEvent(enterFrame){
    	customCursor._x = _root._xmouse;
    }

This is equivalent to the following code, which uses the `getProperty` function:

    onClipEvent(enterFrame){
    	customCursor._x = getProperty(_root, _xmouse);
    }

The `_x`, `_y`, `_rotation`, `_xscale`, `_yscale`, `_height`, `_width`, `_alpha`, and `_visible` properties are affected by transformations on the movie clip's parent, and transform the movie clip and any of the clip's children. The `_focusrect`, `_highquality`, `_quality`, and `_soundbuftime` properties are global; they belong only to the level 0 main Timeline. All other properties belong to each movie clip or loaded level.

For a list of movie clip properties, see MovieClip (object) in the ActionScript Dictionary.