Masking a mc

1

i have a move clip that is loaded through some action script and i would like to apply a mask to it but i cant seem to figure it out. here is my code and i have a movie clip that i need to use as a mask named “Main_Mask”. any suggestions would be great.

Thanks


Stage.scaleMode = 'noScale';

this.dockActions = function(label) {
	switch(label) {
		case 'Preferences':
			trace('Actions here to handle Preferences.');
			break;
		case 'Blog':
			trace('Actions here to handle Blog.');
			break;
		case 'Forum':
			trace('Actions here to handle Forum.');
			break;
		default:
			trace('Default action here.');
	}
}

var dockTemplate = {
	layout: 0, /* top | right | bottom | left | *rotation* */
	icon_size: 200,
	icon_min: 100,
	icon_max: 150,
	icon_spacing: 0,
	items: [
			{ id: 'settings', label: 'Preferences'},
			{ id: 'blog', label: 'Blog' },
			{ id: 'forum',label: 'Forum' },
			{ id: 'shop', label: 'Store' },
			{ id: 'support', label: 'Tech Support' },
			{ id: 'search', label: 'Search Archives' },
			{ id: 'contact', label: 'Contact Us' },
			{ id: 'trash', label: 'Trash' }
			],
	span: null,
	amplitude: null,
	callback: this.dockActions
}

this.attachMovie('Dock', 'menu_mc', 1, dockTemplate);
this.Dock.setMask (Main_Mask)
this.menu_mc._x = Stage.width / 2;
this.menu_mc._y = Stage.height / 2;