//event to check session time variable declaration
var checkSessionTimeEvent;

$(document).ready(function() {
	//event to check session time left (times 1000 to convert seconds to milliseconds)
    checkSessionTimeEvent = setInterval("checkSessionTime()",30*1000);
});

//time session started
var pageRequestTime = new Date();

//session timeout length
var timeoutLength = 1200*1000;

//set time for first warning, ten seconds before session expires
var warningTime = timeoutLength - (30*1000);

//set number of seconds to count down from for countdown ticker
var countdownTime = 30;

function checkSessionTime()
{
	//get time now
	var timeNow = new Date(); 
	
	//event create countdown ticker variable declaration
	var countdownTickerEvent; 	
	
	//difference between time now and time session started variable declartion
	var timeDifference = 0;
	
	timeDifference = timeNow - pageRequestTime;

    if (timeDifference > warningTime && timeDifference < timeoutLength)
        {            
            //call now for initial dialog box text (time left until session timeout)
            countdownTicker(); 
            
            //set as interval event to countdown seconds to session timeout
            countdownTickerEvent = setInterval("countdownTicker()", 1000);
            
            showBox('session_warning');

        }
    else if (timeDifference > timeoutLength){
    		//close warning dialog box
            if (document.getElementById('session_warning').style.display = "block") hideBox('session_warning');
            
            //$("p#dialogText-expired").html(timeDifference);
            showBox('session_expire');
			$('#end_session').load('delete_session.php');
            
             //clear (stop) countdown ticker
            clearInterval(countdownTickerEvent);
			clearInterval(checkSessionTimeEvent);
        }
        
}

function countdownTicker()
{
	//put countdown time left in dialog box
	$("span#dialogText-warning").html(countdownTime);
	
	//decrement countdownTime
	countdownTime--;
}