var refreshScreen;

function addCourse(x)
{
	refreshScreen = x;
	xmlhttp=new XMLHttpRequest();
	var course = document.getElementById("courseName").value;	
	var period = document.getElementById("period").value;
	var url="addCourse.php";
	url=url+"?course="+course;
	url=url+"&period="+period;
	url=url+"&sid="+Math.random();
	xmlhttp.onreadystatechange=stateChangedAddCourse;
	xmlhttp.open("GET",url,true);
	xmlhttp.send(null);
}

function stateChangedAddCourse()
	{
		if (xmlhttp.readyState==4)
		{
	  		document.getElementById("courseMessage").innerHTML = "";
	  		document.getElementById("selectAddOneStudent").innerHTML = xmlhttp.responseText;
	  		document.getElementById("selectImportStudents").innerHTML = xmlhttp.responseText;
	  		document.getElementById("courseMessage").innerHTML = "Course Added";
	  		if(refreshScreen == "yes")
	  		{
	  			location.reload(true);
	  		}
		 }
	}



function removeCourse()
{
	var course = document.getElementById("removeCourse").value;
	
	xmlhttp=new XMLHttpRequest();
	var url="removeCourse.php";
	var params="course="+course;
	params=params+"&sid="+Math.random();
	xmlhttp.onreadystatechange=function(){if(xmlhttp.readyState==4){location.reload(true);}}
	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);
}




function addOneStudent(f)
{
	xmlhttp=new XMLHttpRequest();
	var course = document.getElementById("selectAddOneStudent").value;	
	var firstName = document.getElementById("addOneStudentFname").value;
	var lastName = document.getElementById("addOneStudentLname").value;
	var flag = f;
	if(firstName!=null && lastName!=null && course!='')
	{
		if(confirm("Are you sure that "+firstName+" "+lastName+" should be added to "+course+"?"))
		{
			var url="addOneStudent.php";
			url=url+"?course="+course;
			url=url+"&firstName="+firstName;
			url=url+"&lastName="+lastName;
			url=url+"&flag="+flag;
			url=url+"&sid="+Math.random();
			xmlhttp.onreadystatechange=stateChangedAddOneStudent;
			xmlhttp.open("GET",url,true);
			xmlhttp.send(null);
		}
	}
	else
	{
		alert("I can't possibly add a student who doesn't have a name or destination. We're all looking for our place in the world, please help this student find theirs.");
	}
}

function stateChangedAddOneStudent()
{
	if(xmlhttp.readyState<4)
	{
		document.getElementById("addMessage").innerHTML = "<img src='css/img/wait.gif' />";
	}
	if (xmlhttp.readyState==4)
	{
		document.getElementById("addMessage").innerHTML = xmlhttp.responseText;
	}
}



function removeOneStudent()
{
	var id_number = document.getElementById("removeStudent").value;
	
	xmlhttp=new XMLHttpRequest();
	var url="removeStudent.php";
	var params="id="+id_number;
	params=params+"&sid="+Math.random();
	xmlhttp.onreadystatechange=function()
	{
		if(xmlhttp.readyState==4)
		{
			document.getElementById("addMessage").innerHTML = xmlhttp.responseText;
		}
	};
	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);
}



function editCoursesPopUp()
{
	removeAssessments();	
	var Box = document.getElementById('table_wrapper');
	scoreBox = document.createElement('div');
	scoreBox.setAttribute('id', "scoreBox");
	
	scoreBox.style.left = mouseX;
	scoreBox.style.top = mouseY;

	//innerHTML of scoreBox comes from AJAX-php
	xmlhttp=new XMLHttpRequest();
	var url="getEditCoursesPopUp.php";
	url=url+"?sid="+Math.random();
	xmlhttp.onreadystatechange=stateChangedEditCoursesPopUp;
	xmlhttp.open("GET",url,true);
	xmlhttp.send(null);
	
	//place box using absolute positioning where the mouse clicked?
	
	Box.appendChild(scoreBox);
	box_flag = 1;
}

function stateChangedEditCoursesPopUp()
{
	if (xmlhttp.readyState==4)
	{
		document.getElementById("scoreBox").innerHTML= xmlhttp.responseText;
	}
}

function changeFinalGradeComp()
{
        course = document.getElementById("finalGradeCompCourse").value;
        method = document.getElementById("finalGradeCompMethod").value;
        xmlhttp=new XMLHttpRequest();
	var url="changeFinalGradeComp.php";
	url=url+"?sid="+Math.random();
	url=url+"&course="+course;
	url=url+"&method="+method;
	xmlhttp.onreadystatechange=stateChangedChangeFinalGradeComp;
	xmlhttp.open("GET",url,true);
	xmlhttp.send(null);
}

function stateChangedChangeFinalGradeComp()
{
	if (xmlhttp.readyState==4)
	{
		document.getElementById("changeFinalGradeComp").innerHTML= xmlhttp.responseText;
	}
}



function showPasswords(){
	xmlhttp=new XMLHttpRequest();
	url="getStudentPasswords.php";
	url=url+"?sid="+Math.random();
	xmlhttp.onreadystatechange=showStudentPasswords;
	xmlhttp.open("GET",url,true);
	xmlhttp.send(null);
}

function showStudentPasswords(){
	if(xmlhttp.readyState == 4)
	{
		document.getElementById("controlWrapper").innerHTML = xmlhttp.responseText;
	}
}