var g_timeID;

var g_x_initialPosition = 0;
var g_y_initialPosition = 0;
var g_x_positionNow = 0;
var g_y_positionNow = 0;
var g_x_limitDistance;
var g_y_limitDistance;
var g_x_maxPosition;
var g_y_maxPosition;

function startScroll( direction, speed, contentLayerName, boxLayerName ) {
	speed = 5;
	var contentHeight;
	var contentWidth;
	var boxHeight;
	if( direction == 'up' || direction == 'down' ) {
		contentHeight = getHeightLAYER( contentLayerName );
		boxHeight = getHeightLAYER( boxLayerName );

		//g_y_positionNow = getTopLAYER( contentLayerName );
		//g_x_positionNow = getLeftLAYER( contentLayerName );
		
		g_y_limitDistance = contentHeight - boxHeight;
		g_y_maxPosition = g_y_initialPosition - g_y_limitDistance;

		//alert( g_y_positionNow + "=" + g_x_positionNow + "=" + g_y_limitDistance + "=" + g_y_maxPosition );
		if( contentHeight > boxHeight ) {
			if( g_y_positionNow > g_y_maxPosition && direction == 'up' ) {
					g_y_positionNow = g_y_positionNow - speed;
			} else if ( g_y_positionNow < g_y_initialPosition && direction == 'down' ) {
					g_y_positionNow = g_y_positionNow + speed;
			}
			if( g_y_positionNow < g_y_maxPosition ) {
				g_y_positionNow = g_y_maxPosition;
			} else if( g_y_positionNow > g_y_initialPosition ) {
				g_y_positionNow = g_y_initialPosition;
			}
		}
		//alert( g_y_positionNow + "=" + g_x_positionNow + "=" + g_y_limitDistance + "=" + g_y_maxPosition );
		moveToLAYER( contentLayerName, g_x_positionNow, g_y_positionNow );
	}
	
	g_timeID = setTimeout( "startScroll( '" + direction + "', " + speed + ", '" + contentLayerName + "', '" + boxLayerName + "')", 30 );
}


function stopScroll() {
	clearTimeout( g_timeID );
}

function initScroll( contentLayerName ) {
	g_y_initialPosition = getTopLAYER( contentLayerName );
	g_x_initialPosition = getLeftLAYER( contentLayerName );
}