function calculate() {
	var T = document.getElementById("T").value;
	var G = document.getElementById("G").value;
	var Ip = document.getElementById("Ip").value;
	var theta;
	if(T != "" && G != "" && Ip != ""){
		T = parseFloat(T);
		G = parseFloat(G);
		Ip = parseFloat(Ip);
		theta = (T/(G*Ip));
		document.getElementById("theta").innerHTML = "theta: " + theta;
	}
}