function doExchange(d){
	var s = d.elements['startCoin'].value;
	var t = d.elements['targetCoin'].value;
	var a = d.elements['amount'].value;
	$.get("http://api.fixer.io/latest?base=" + s + "&symbols=" + t,function(data){
		var b = data['rates'][t];
		var result = (a * b).toPrecision(5);
		document.body.innerHTML += result;

	});
	return false;
}