var ladegrafik = '../pics/website/plan_load.gif';
	var left = 0;
	var top = 0;
	var zoom = 1;
	var width = 5000;
	var height = 3563;
	var step;

	function turnup()
	{
		if (zoom > 1)
		{
			document.planform.plan.src = ladegrafik;
			step = height / zoom - 200;
			top = top - step;
			if (top < 0){top = 0;}
			generate();
		}
	}
	function turndown()
	{
		if (zoom > 1)
		{
			document.planform.plan.src = ladegrafik;
			step = height / zoom - 200;
			top = top + step;
			if (top + step > height){top = height - step;}
			generate();
		}
	}
	function turnleft()
	{
		if (zoom > 1)
		{
			document.planform.plan.src = ladegrafik;
			step = width / zoom - 200;
			left = left - step;
			if (left < 0){left = 0;}
			generate();
		}
	}
	function turnright()
	{
		if (zoom > 1)
		{
			document.planform.plan.src = ladegrafik;
			step = width / zoom - 200;
			left = left + step;
			if (left + step > width){left = width - step;}
			generate();
		}
	}
	function zoomin()
	{
		if (zoom <= 7)
		{
			document.planform['zoom' + zoom].src = '../pics/website/pixel_gray.gif';
			document.planform.plan.src = ladegrafik;
			zoom = zoom + 1;
			generate();
		}
	}
	function zoomout()
	{
		if (zoom > 1)
		{
			document.planform['zoom' + zoom].src = '../pics/website/pixel_gray.gif';
			document.planform.plan.src = ladegrafik;
			zoom = zoom - 1;

			step=width/zoom-200;
			if (left + step > width){left = width - step;}
			step=height/zoom-200;
			if (top + step > height){top = height - step - 200;}
			if (left < 0){left=0;}
			if (top < 0){top=0;}

			generate();
		}
	}
	function zoomset(zoomsetzoom)
	{
		document.planform['zoom' + zoom].src = '../pics/website/pixel_gray.gif';
		document.planform.plan.src = ladegrafik;
		zoom = zoomsetzoom;
		generate();
	}
	function positionset()
	{
		if (document.planform.strasse.options[document.planform.strasse.selectedIndex].value)
		{
			document.planform['zoom' + zoom].src = '../pics/website/pixel_gray.gif';
			document.planform.plan.src = ladegrafik;
			
			position = document.planform.strasse.options[document.planform.strasse.selectedIndex].value;
			var positiondata = position.split(',');

			zoom=7;
			left = Math.round(positiondata[0] - width / zoom / 2);
			top = Math.round(positiondata[1] - height / zoom / 2);
			
			document.planform.strasse.selectedIndex = 0;

			generate();
		}
	}
	function generate()
	{
		document.planform.plan.src = ladegrafik;
		document.planform['zoom' + zoom].src = '../pics/website/pixel_black.gif';
		
		var rand = Math.ceil(Math.random() * 1000) % 1000 + 1;
		document.planform.plan.src = 'plan.pl?action=generate&left=' + left + '&top=' + top + '&zoom=' + zoom + '&rand=' + rand;
	}
	function lage()
	{
		document.planform.plan.src = '../pics/website/plan_tirol.gif';
	}