var zoom = 200; // startup zoom both for helix and for base pairs is 200
/*
The zoom value in the move command is ADDED to the present zoom.
So, to go from 100% to 200%, +100.
To go from 100% to 50%, -50.
*/

function two_x()
{
	var oldzoom;
	var addzoom;
	if ((zoom * 2) <= 800)
	{
		addzoom = (zoom * 2) - zoom;
		oldzoom = zoom;
		zoom *= 2;
//		alert (oldzoom + " + " + addzoom + " = " + zoom);
		scriptToChime("zoom " + oldzoom + ";move 0 0 0 " + addzoom + " 0 0 0 0 2 30 10;");
	}
	else
	{
		scriptToChime("zoom " + zoom + ";");
		alert("Sorry, this is as big as we get.");
	}
}
function half_x()
{
	var oldzoom;
	var subzoom;
	if ((zoom / 2) >= 25)
	{
		subzoom = zoom - (zoom / 2);
		oldzoom = zoom;
		zoom /= 2;
		scriptToChime("zoom " + oldzoom + ";move 0 0 0 -" + subzoom + " 0 0 0 0 2 30 10");
	}
	else
	{
		scriptToChime("zoom " + zoom + ";");
		alert("Sorry, this is as small as we get.");
	}
}