function GetXmlHttpObject(){
	var xmlHttp = null;
	try{
		// Firefox, Opera 8.0+, Safari
		xmlHttp = new XMLHttpRequest();
	}catch (e){
		//Internet Explorer
		try{
			xmlHttp = new ActiveXObject("Msxml2.XMLHTTP");
		}catch (e){
			xmlHttp = new ActiveXObject("Microsoft.XMLHTTP");
		}
	}
	return xmlHttp;
}

function get_package_prices(id_package){
	xmlHttp = GetXmlHttpObject();
	if(xmlHttp == null){
		alert ("Browser does not support HTTP Request!");
		return;
	}
	
	var url = "ajax-price-packages.php?id_package=" + id_package;
	
	xmlHttp.open("GET", url, true);
	
	xmlHttp.onreadystatechange = function(){
		if(xmlHttp.readyState == 4 || xmlHttp.readyState == "complete"){
			element = document.getElementById('div-months');
			if(element != null){
				element.innerHTML = xmlHttp.responseText;
			}
		}
	}
	
	xmlHttp.send(null);
}