if (navigator.appName == "Netscape") {
	alert("WARNING: The MedCalc Pregnancy Wheel does NOT work with Netscape browsers.\n\n" +
	"This program is optimized for Microsoft Internet Explorer.");
}

function RotateZ() {
    innerWheel.SetIdentity();
    Seq.item('ActionSet3').Play();
	innerWheel.SetIdentity();
}

function RotateZaxis() {
	var xval = pregxy.xval.value;
	var yval = pregxy.yval.value;
	var addRotate = pregxy.addRotate.value;
	var rotatePosition = pregxy.rotatePosition.value;
	var isedd = pregxy.whichLine.selectedIndex;

	if (!xval) {
		var xlen = 400;
		var ylen = 0;
	} else {
		var xlen = xval - 300;
		var ylen = yval - 300;
	}
	var angleRad = Math.atan2(ylen, xlen);
	var angle = angleRad * 360 / (2 * Math.PI);
	if (isedd == 1) {angle = angle - 276;}		//  Estim Due Date chosen
	angle = roundNum(angle,0);
	angle += 90 * addRotate;
	while (angle > 360) {angle = angle - 360;}
	while (angle < 0) {angle += 360;}

	//  Re-center inner wheel, when outer wheel is rotated
	//		(slight discrepancy between the centers of inner and outer wheel)
	if (rotatePosition == 0) {
		innerWheel.style.top = "125";
		innerWheel.style.left = "86";
	}
	if (rotatePosition == 1) {
		innerWheel.style.top = "126";
		innerWheel.style.left = "90";
	}
	if (rotatePosition == 2) {
		innerWheel.style.top = "131";
		innerWheel.style.left = "83";
	}
	if (rotatePosition == 3) {
		innerWheel.style.top = "124";
		innerWheel.style.left = "86";
	}
	
	innerWheel.Rotate(0,0,angle);
}

function mapCoord() {
//	alert ("x = " + window.event.offsetX + "\ny = " + window.event.offsetY);
	alert ("x = " + xval + "\ny = " + yval);

//	var x = window.event.offsetX;
//	var y = window.event.offsetY;
	RotateZ();
}

function rotateOuter(lr) {
	rotatePosition = pregxy.rotatePosition.value;
	addRotate = pregxy.addRotate.value;
	
	if (lr == "l") {	//  rotate counterclockwise
		if (rotatePosition == 0) {rotatePosition = 4;}
		if (addRotate == 0) {addRotate = 4;}
		rotatePosition--;
		addRotate--;
	} else {			//  rotate clockwise
		if (rotatePosition == 3) {rotatePosition = -1;}
		if (addRotate == 3) {addRotate = -1;}
		rotatePosition++;
		addRotate++;
	}

	outerWheel.style.filter="progid:DXImageTransform.Microsoft.BasicImage(rotation=" + rotatePosition;
	pregxy.rotatePosition.value = rotatePosition;
	pregxy.addRotate.value = addRotate;
	RotateZ();
}

function roundNum(number,decimal) {
	multiplier = Math.pow(10,decimal);
	number = Math.round(number * multiplier) / multiplier;
        return number
}