function createRequestObject(){
	var request_o; //declare the variable to hold the object.
	var browser = navigator.appName; //find the browser name
	if(browser == "Microsoft Internet Explorer"){
		/* Create the object using MSIE's method */
		request_o = new ActiveXObject("Microsoft.XMLHTTP");
	}else{
		/* Create the object using other browser's method */
		request_o = new XMLHttpRequest();
	}
	return request_o; //return the object
}

var http = createRequestObject(); 

//-------------------------------
//get days
//--------------------------------
function getDays(){
	http.open('get', 'internal_get_days.php?action=get_days&id=' 
			+ document.form_reservation.select_month_select.selectedIndex);
	http.onreadystatechange = handleMonth; 
	http.send(null);
}

function handleMonth(){
	if(http.readyState == 4){ //Finished loading the response
		var response = http.responseText;
		document.getElementById('days_of_the_month').innerHTML = response;
	}
}