function ch_box(box_id)
{
	var box = document.getElementById(box_id);
			var box_img = document.getElementById('img_' + box_id);	
	if (box.value == 'Y')
	{

		box.value = 'N';
		
		box_img.style.background = "url(/images/chk_off.png) no-repeat";
	}
	else
	{
		box.value = 'Y';
		box_img.style.background = "url(/images/chk_on.png) no-repeat";	
	}	
		
	
}