var xmlHttp
/* 
	Purpose: Creates an HttpObject
	Results: If successful returns a HttpObject; else error
	Page(s) of use: forum.php
*/
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;
}

/*
	Used on blog.php. 
	User selects from a drop down box a subteam.
	Calls viewSubTeamNotes to display all notes generated by that team
*/
function stateChanged_blog()
{
	if (xmlHttp.readyState==4)
	{	
		if(xmlHttp.responseText == "error")
			alert("There was an error. Please try again.");
		else
		{
			document.getElementById("blogWindow").innerHTML = xmlHttp.responseText;
		}
	}
}

function subTeamNotes(subTeamId) 
{
	xmlHttp=GetXmlHttpObject();
	if (xmlHttp==null)
	{
		alert ("Your browser does not support AJAX!");
		return;
	} 
	
	var url = "component/viewSubTeamNotes.php";
	url = url + "?subTeamId=" + subTeamId;
	
	xmlHttp.onreadystatechange = stateChanged_blog;
	xmlHttp.open("GET",url,true);
	xmlHttp.send(null);
}

/*
	Used on blog.php. 
	Logged in user can enter new blog information to be load to the database
	Calls blog_insert to insert the information
*/
function stateChanged_newBlog()
{
	if (xmlHttp.readyState==4)
	{	
		if(xmlHttp.responseText == "error")
			alert("There was an error. Please try again.");
		else
		{
			subTeamNotes(xmlHttp.responseText);
		}
	}
}

function newBlog(member_id, blog_Content, subGroupSelect, topic) 
{
	xmlHttp=GetXmlHttpObject();
	if (xmlHttp==null)
	{
		alert ("Your browser does not support AJAX!");
		return;
	} 
	
	var url = "component/blog_insert.php";
	
	var params = "memberId=" + member_id; 
	params = params + "&blogContent=" + blog_Content.value;
	params = params + "&subGroupSelect=" + subGroupSelect.value;
	params = params + "&topic=" + topic.value;
	
	xmlHttp.open('POST', url, true);
	xmlHttp.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
      	xmlHttp.setRequestHeader("Content-length", params.length);
      	xmlHttp.setRequestHeader("Connection", "close");
      	xmlHttp.send(params);
   	xmlHttp.onreadystatechange = stateChanged_newBlog;	
}