Отправка данных с формы в формате JSON на сервер

		var inpName = document.querySelector('#name'); 
		var inpPhone = document.querySelector('#phone'); 
		var inpEmail = document.querySelector('#email'); 
		var inpMessage = document.querySelector('#message'); 
 
	function ajax(params) { 
		var xhr = new XMLHttpRequest(); 
 
		xhr.onreadystatechange = function() { 
			if (xhr.readyState == 4 && xhr.status == 200) { 
				console.log('readyState: ' + xhr.readyState + ' status: ' + xhr.status); 
			} 
		} 
 
		xhr.open('POST', 'http://localhost:8080/sendmail'); 
		xhr.responseType = 'json'; 
		xhr.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded'); 
		xhr.send(params); 
} 
 
var formSend = document.querySelector('input[type="button"]'); 
 
formSend.addEventListener('click', function() { 
	var params = "name=" + inpName.value + "&" + "phone=" + inpPhone.value + "&" + "email=" + inpEmail.value + "&" + "message=" + inpMessage.value; 
	ajax(params); 
});