function arrow_switcher(id)
{
	// menu1-8 (m1 to m8)
	for(i = 1; i <= 8; i++)	{
		document.getElementById('m' + i).src = 'images/blind.gif';
	}

	// menu2 (m2) with 3 submenues (sX)
	for(i = 1; i <= 3; i++)	{
		document.getElementById('m2s' + i).src = 'images/blind.gif';
	}

	// menu3 (m3) with 2 submenues (sX)
	for(i = 1; i <= 2; i++)	{
		document.getElementById('m3s' + i).src = 'images/blind.gif';
	}

	// menu4 (m4) with 2 submenues (sX)
	for(i = 1; i <= 2; i++)	{
		document.getElementById('m4s' + i).src = 'images/blind.gif';
	}
		
	if (id != '')	{
		document.getElementById(id).src = 'images/pfeil.gif';
	}
}