var xval = 'distance';
var yval1 = 'alt';
var yval2 = 'speed';
var ysize = 800;
var run_name = '';
var overlay = null;

function graph()
{
	var old_overlay = overlay;
	overlay = new GScreenOverlay( 'graph.cgi?run=' + run_name + '&xtype=' + xval +'&ytype1=' + yval1 + '&ytype2=' + yval2 + '&ysize=' + ysize,
		new GScreenPoint(2, 2, 'pixels', 'pixels'),  // screenXY
		new GScreenPoint(0, 0),  // overlayXY
		new GScreenSize(ysize, 250)  // size on screen
		);
	map.addOverlay(overlay);

	if (old_overlay != null) {
		old_overlay.remove();
	}
}

function setxaxis(who)
{
	xval = who.value;
	graph();
}

function setyaxis1(who)
{
	yval1 = who.value;
	graph();
}

function setyaxis2(who)
{
	yval2 = who.value;
	graph();
}

function hide(who)
{
	overlay.hide()
}

function show(who)
{
	overlay.show()
}

function graph_init(FORM_run,width)
{
	run_name = FORM_run;
	ysize = width;
}