// JavaScript Document
function getHeartZones(){
//get threshold heart rate zone
	var hr = document.heartZonesForm.thresholdId.value;
	hr = parseInt(hr);

//calculate zones for user
	var z1low = Math.round(hr*0.655);
	var z1high = Math.round(hr*0.812);
	var z2low = (z1high+1);
	var z2high = Math.round(hr * 0.888);
	var z3low = (z2high+1);
	var z3high = Math.round(hr * 0.935);
	var z4low = (z3high+1);
	var z4high = hr;
	//var z5low = (hr+1);
	//var z5high = "max";

//fill in values into form
	document.heartZonesForm.z1low.value = z1low;
	document.heartZonesForm.z1high.value = z1high;
	document.heartZonesForm.z2low.value = z2low;
	document.heartZonesForm.z2high.value = z2high;
	document.heartZonesForm.z3low.value = z3low;
	document.heartZonesForm.z3high.value = z3high;
	document.heartZonesForm.z4low.value = z4low;
	document.heartZonesForm.z4high.value = z4high;
	//document.heartZonesForm.z5low.value = z5low;
	//document.heartZonesForm.z5high.value = z5high;
}
//power zones calculator
function getPowerZones(){
	
//get threshold heart rate 
	var hr = document.powerZonesForm.thresholdId.value;
	hr = parseInt(hr);

//calculate zones for user
	var z1high = Math.round(hr*0.55);
	var z2low = (z1high+1);
	var z2high = Math.round(hr * 0.75);
	var z3low = (z2high+1);
	var z3high = Math.round(hr * 0.9);
	var z4low = (z3high+1);
	var z4high = Math.round(hr*1.05);
	//var z5low = (z4high+1);
	//var z5high = "max";

//fill in values into form
	document.powerZonesForm.z1high.value = z1high;
	document.powerZonesForm.z2low.value = z2low;
	document.powerZonesForm.z2high.value = z2high;
	document.powerZonesForm.z3low.value = z3low;
	document.powerZonesForm.z3high.value = z3high;
	document.powerZonesForm.z4low.value = z4low;
	document.powerZonesForm.z4high.value = z4high;
	//document.powerZonesForm.z5low.value = z5low;
	//document.powerZonesForm.z5high.value = z5high;
}