var xmlHttp;

function check_inputq()
{
	var error="";
	if(!isEmpty('question'))
		error=error+" Please enter a question.\n";
	if(!isEmpty('username'))
		error=error+" Please enter a username.";
	if (error=="")
		return true;
	else
	{
		alert(error);
		return false;
	}
}
function check_contact()
{
	var error="";
	
	if(!isEmpty('email')){
		error=error+" Please enter your email address.\n";
	}
	else
	{
		if(!emailValidator('email'))
			error=error+" Please enter a valid email.\n";
	}
	if(!isEmpty('subject'))
		error=error+" Please enter a subject.";
	if(!isEmpty('message'))
		error=error+" Please enter an message.";
	if (error=="")
		return true;
	else
	{
		alert(error);
		return false;
	}
}
function check_login()
{
	var error="";
	
	if(!isEmpty('username'))
		error=error+" Please enter a username.\n";
	if(!isEmpty('password'))
		error=error+" Please enter a password.";
	if (error=="")
		return true;
	else
	{
		alert(error);
		return false;
	}
}
function check_register()
{
	var error="";

	if(!isEmpty('username'))
		error=error+" Please enter a username.\n";
	if(!isEmpty('fname'))
		error=error+" Please enter your first name.\n";
	if(!isEmpty('lname'))
		error=error+" Please enter your last name.\n";
	if(!isEmpty('email')){
		error=error+" Please enter your email.\n";
	}
	else
	{
		if(!emailValidator('email'))
			error=error+" Please enter a valid email.\n";
	}
	if(!isEmpty('password'))
		error=error+" Please enter a password.\n";
	if(!isEmpty('passwordb'))
		error=error+" Please enter both matching passwords.\n";
//	if(!pwcomare('password', 'passwordb'))
//		error=error+" Passwords don't match.";
	if (error=="")
		return true;
	else
	{
		alert(error);
		return false;
	}
}
function isEmpty(id){
	if(document.getElementById(id).value.length == 0)
		return false;
	else
		return true;
}
function emailValidator(id)
{
	var emailExp = /^[\w\-\.\+]+\@[a-zA-Z0-9\.\-]+\.[a-zA-z0-9]{2,4}$/;
	if(document.getElementById(id).value.match(emailExp))
		return true;
	else
		return false;
}
function pwcompare(idpwa, idpwb)
{
	var pwa=document.getElementById(idpwa).value;
	var pwb=document.getElementById(idpwb).value;
	if(pwa==pwb)
		return true;
	else
		return false;
}
function loadQnA(category, user)
{
	xmlHttp=GetXmlHttpObject();
	if (xmlHttp==null)
	{
		alert ("Browser does not support HTTP Request");
		return;
	} 
	var url="getQnAs.php";
	url=url+"?category="+category;
	url=url+"&user="+user;
	url=url+"&sid="+Math.random();
	xmlHttp.onreadystatechange=stateChanged;
	xmlHttp.open("GET",url,true);
	xmlHttp.send(null);
} 
function askQuestion(form)
{
	var question = form.question.value;
	var user = "";
	//var dateasked = "2007-04-13";
	var category = "";
	
	if (question.length==0)
	{ 
		return;
	}
	xmlHttp=GetXmlHttpObject();
	if (xmlHttp==null)
	{
		alert ("Browser does not support HTTP Request");
		return;
	} 
	var url="addQuestion.php";
	url=url+"?q="+question;
	url=url+"&u="+user;
	//url=url+"&da="+dateasked;
	url=url+"&c="+category;
	url=url+"&sid="+Math.random();
	xmlHttp.onreadystatechange=stateChanged;
	xmlHttp.open("GET", url, true);
	xmlHttp.send(null);
} 
function stateChanged() 
{ 
	if (xmlHttp.readyState==4 || xmlHttp.readyState=="complete")
	{ 
		document.getElementById("txtQuestions")
		.innerHTML=xmlHttp.responseText;
	} 
}
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;
}