function toggle(div_id) 
{
	var el = document.getElementById(div_id);
	
	if ( el.style.display == 'none' ) 
	{	
		el.style.display = 'block';
	}
	else 
	{
		el.style.display = 'none';
	}
}

function blanket_size(popUpDivVar) 
{
	if (typeof window.innerWidth != 'undefined') 
	{
		viewportheight = window.innerHeight;
	} 
	else 
	{
		viewportheight = document.documentElement.clientHeight;
	}
	
	if ((viewportheight > document.body.parentNode.scrollHeight) && (viewportheight > document.body.parentNode.clientHeight)) 
	{
		blanket_height = viewportheight;
	} 
	else 
	{
		if (document.body.parentNode.clientHeight > document.body.parentNode.scrollHeight) 
		{
			blanket_height = document.body.parentNode.clientHeight;
		}
		else 
		{
			blanket_height = document.body.parentNode.scrollHeight;
		}
	}
		
	var blanket = document.getElementById('blanket');
	blanket.style.height = '1800px';// blanket_height + 'px';
	// blanket.style.width  = '1500px';
	
	var popUpDiv = document.getElementById(popUpDivVar);
	// popUpDiv_height=(blanket_height/2)-250; // half popup's height
	// popUpDiv.style.top = popUpDiv_height + 'px';
}

function window_pos(popUpDivVar) 
{
	if (typeof window.innerWidth != 'undefined') 
	{
		viewportwidth = window.innerHeight;
	} 
	else 
	{
		viewportwidth = document.documentElement.clientHeight;
	}
	
	if ((viewportwidth > document.body.parentNode.scrollWidth) && (viewportwidth > document.body.parentNode.clientWidth)) 
	{
		window_width = viewportwidth;
	} 
	else 
	{
		if (document.body.parentNode.clientWidth > document.body.parentNode.scrollWidth) 
		{
			window_width = document.body.parentNode.clientWidth;
		} 
		else 
		{
			window_width = document.body.parentNode.scrollWidth;
		}
	}

	blanket.style.width = window_width + 'px';
	
	var popUpDiv = document.getElementById(popUpDivVar);

	window_width=(window_width/2)-315; // half popup's width
	popUpDiv.style.left = window_width + 'px';
}

function popup(windowname) 
{
	blanket_size(windowname);
	window_pos(windowname);
	toggle('blanket');
	toggle(windowname);		
}