function navichange( aktuellenavigation )
{
	line = document.getElementById( aktuellenavigation );
	for( var i = 1; i <= 4; i++ )
	{
		line1 = "unternavi" + i;
		if ( line1 != aktuellenavigation )
		{
			line2 = document.getElementById( line1 );
			line2.style.display = "none";
		}
	}
	line.style.display = "block";
}