var VIEWER_DEFAULT_HEIGHT = 143;
var VIEWER_ACTION_SPEED = 10;
var curr_height = VIEWER_DEFAULT_HEIGHT;
var viewer_status = "open";
var viewer_interval = null;

function OpenViewer()
{
	if(viewer_status == "close")
	{
		viewer_status = "open";
		
		if(viewer_interval != null)
		{
			viewer_interval = null;
		}
		
		viewer_interval = window.setInterval(SetViewerHeight, 20);
	}
}

function CloseViewer()
{
	if(viewer_status == "open")
	{
		viewer_status = "close";
		
		if(viewer_interval != null)
		{
			viewer_interval = null;
		}
		
		viewer_interval = window.setInterval(SetViewerHeight, 20);
	}
}

function SetViewerHeight()
{
	if(viewer_status == "close" && curr_height <= VIEWER_ACTION_SPEED)
	{
		curr_height = 1;
		
		if(viewer_interval != null)
		{
			window.clearInterval(viewer_interval);
			viewer_interval = null;
		}
	}
	else if(viewer_status == "open" && curr_height >= VIEWER_DEFAULT_HEIGHT)
	{
		curr_height = VIEWER_DEFAULT_HEIGHT
		
		if(viewer_interval != null)
		{
			window.clearInterval(viewer_interval);
			viewer_interval = null;
		}
	}
	else
	{
		if(viewer_status == "open")
		{
			curr_height += VIEWER_ACTION_SPEED;
		}
		else if(viewer_status == "close")
		{
			curr_height -= VIEWER_ACTION_SPEED;
		}
		else
		{
			return;
		}
	}
	
	$("home_view_cot").style.height = curr_height + "px";
}