function calculate() {
	var r = document.getElementById("r").value;
    var h = document.getElementById("r").value;
	var sa;
	if(r != "" && h != ""){
		r = parseFloat(r);
        h = parseFloat(h);
		sa = (((2)*(3.14)*(r*r)) + ((2)*(3.14)*(r)*(h)));
		document.getElementById("Surface Area").innerHTML = "Surface Area: " + sa;
	}
}