var timercount = 0;
var timeremain = 0;
var timestart  = null;

function showtimer() {
	
	clearTimeout(timercount);
	
	var timeend = new Date();
	var timedifference = timeremain - (timeend.getTime() - timestart.getTime());
	
	if (timedifference < 30000) {
		document.timeform.timetextarea.style.color = '#f00';
	}
	
	if (timedifference < 1) {
		//window.location = "submit.html";
	}
	
	if (timedifference > 0) {
		timeend.setTime(timedifference);
		var minutes_passed = timeend.getMinutes();
		if(minutes_passed < 10){
			minutes_passed = "0" + minutes_passed;
		}
		var seconds_passed = timeend.getSeconds();
		if(seconds_passed < 10){
			seconds_passed = "0" + seconds_passed;
		}
		document.timeform.timetextarea.value = minutes_passed + ":" + seconds_passed;
		timercount = setTimeout("showtimer()", 1000);
	}
	else {
		document.timeform.timetextarea.value = '00:00';
	}
	
}

function sw_start()
{
	var time = document.timeform.timetextarea.value;
//alert(time);
	timeremain = 1000 * ((parseInt(time.substring(0,2)) * 60) + parseInt(time.substring(3)));
	timestart  = new Date();
	timercount = setTimeout("showtimer()", 1000);
}