var xmlHttp;
	
	function createXMLHttpRequest() {
		if ( window.ActiveXObject ) {
			xmlHttp = new ActiveXObject("Microsoft.XMLHTTP");
		} else if ( window.XMLHttpRequest ) {
			xmlHttp = new XMLHttpRequest();
		}
	}

	function inquiry_check() {
		var get_name = document.getElementById("name").value;
		var get_company = document.getElementById("company").value;
		var get_email = document.getElementById("email").value;
		var get_phone = document.getElementById("phone").value;
		var get_subject = document.getElementById("subject").value;
		var get_message = document.getElementById("message").value;

		params = 
		"name=" + get_name + 
		"&company=" + get_company + 
		"&email=" + get_email + 
		"&phone=" + get_phone + 
		"&subject=" + get_subject + 
		"&message=" + get_message;

		createXMLHttpRequest();
		xmlHttp.onreadystatechange = outputInquiry_check;
		xmlHttp.open("GET","../ajax/ajax_check_contact.php?" + params, true);
		xmlHttp.send(null);
	}

	function outputInquiry_check() {
		if ( xmlHttp.readyState == 4 && xmlHttp.status == 200 ) {
			if ( xmlHttp.responseText == 'email' ) {
				document.getElementById("error_box").innerHTML = 'Please enter a valid e-mail address.';
			} else if ( xmlHttp.responseText == 'email2' ) {
				document.getElementById("error_box").innerHTML = 'Please enter a valid e-mail address.';
			} else if ( xmlHttp.responseText == 'name' ) {
				document.getElementById("error_box").innerHTML = 'Please enter a name.';
			} else if ( xmlHttp.responseText == 'message' ) {
				document.getElementById("error_box").innerHTML = 'Please enter a message.';
			} else {
				document.getElementById("knop").innerHTML = '';
				document.getElementById("error_box").innerHTML = 'Message sent.';
			}
		}
	}

	function change_month(month, year) {
		params = 
		"month=" + month + 
		"&year=" + year;
		
		createXMLHttpRequest();
		xmlHttp.onreadystatechange = outputCalendar;
		xmlHttp.open("GET","../ajax/ajax_change_month.php?" + params, true);
		xmlHttp.send(null);
	}

	function outputCalendar() {
		if ( xmlHttp.readyState == 4 && xmlHttp.status == 200 ) {
			document.getElementById("calendar").innerHTML = xmlHttp.responseText;
		}
	}