MOVING_MENU_WIDTH = 200;
MOVING_MENU_TOP_LIMIT = 103;
MOVING_MENU_POSITION_LEFT = 10;
THREAD_BBS_WIDTH = 780;
menu_move_span = new Array(
	2000, 1000, 500, 400, 300,
	290, 280, 270, 260, 250, 200
);
menuMovingID = null;
window.onresize = resetAndInit;
obj = null;
obj_y = null;
function movingMenuInit(){
	obj = document.getElementById("movingMenu");
	obj.style.display = "block";
	//document.getElementById("testLayer").innerHTML = document.body.scrollWidth;
	window_width = document.body.scrollWidth;
	obj.style.left = (window_width/2) - (THREAD_BBS_WIDTH/2) + MOVING_MENU_POSITION_LEFT;
	obj.style.top = MOVING_MENU_TOP_LIMIT;
	obj_y = MOVING_MENU_TOP_LIMIT;
	menuMovingID = setInterval('menuMoving()', 10);
}
function menuMoving(){
	var diff;
	var now_y = (getScrollY()+MOVING_MENU_TOP_LIMIT);
	if(obj_y <= now_y){
		diff = now_y - obj_y;
		obj_y = obj_y + getMoveSpan(diff);
	}
	if(obj_y >= now_y){
		diff = obj_y - now_y;
		obj_y = obj_y - getMoveSpan(diff);
	}
	obj.style.top = obj_y;
	//document.getElementById("testLayer").innerHTML = "[diff:"+diff+"]<br>["+obj_y+"]<br>["+getScrollY()+"]";
}
function getScrollY(){
	var y = document.body.scrollTop || document.documentElement.scrollTop;
	return y;
}
function getMoveSpan(diff){
	for(i = 0;i < menu_move_span.length;i++){
		if(diff >= menu_move_span[i]){
			return menu_move_span[i]-50;
		}
	}
	return 5;
}
function resetAndInit(){
	clearInterval(menuMovingID);
	setTimeout("movingMenuInit()", 10);
}