var layer_event = true;

function check_layer(id)
{
	if(layer_event == true)
	{
		var e = document.getElementById(id);
		e.checked = !e.checked;
		check_track(e, false);
	}
	layer_event = true;
}
function check_track(e, lv)
{
	var all_ch = true;
	if(lv)
		layer_event = false;
	//var e = document.getElementById(id);
	if (!e.checked)
	{
		document.getElementById('bg_'+e.value).style.backgroundColor = '';
		document.getElementById('selall').checked = false;
	}
	else
	{
		document.getElementById('bg_'+e.value).style.backgroundColor = '#d4d4c5';
		ts = document.getElementsByName('tids[]');
		for (k = 0; k < ts.length; k++)
		{
			if (!ts[k].checked)
			{
				all_ch = false;
				break;
			}
		}
	}
	if(all_ch && e.checked)
		document.getElementById('selall').checked = true;
	calc();
	return true;
}

function check(ch)
{
	ts = document.getElementsByName('tids[]');
	for (k = 0; k < ts.length; k++)
	{		
		if (ts[k].checked != ch.checked)
		{
			ts[k].checked = ch.checked;
			if(ch.checked == true)
				document.getElementById('bg_'+ts[k].value).style.backgroundColor = '#d4d4c5';
			else
				document.getElementById('bg_'+ts[k].value).style.backgroundColor = '';
		}
	}
	calc();
	return true;		
}
function calc()
{
	var discount = 0;
	var n_ch = 0;
	var ch_dr = 0;
	var ch_sz = 0;
	var price = 0;
	ts = document.getElementsByName('tids[]');
	for (k = 0; k < ts.length; k++)
	{
		if (ts[k].checked)
		{
			ch_sz += sz[ts[k].value];
			ch_dr += dr[ts[k].value];
			n_ch++;
		}
	}
	if(n_ch == ts.length && n_ch == total)
	{
		price = Math.round(n_ch*track_price*0.8);
		discount = 1;
	}
	else
		price = Math.round(n_ch*track_price);
	price /= 100;
	if((price - Math.floor(price)) == 0)
		price = price+'.00';
	else if( Math.round(((price - Math.floor(price))*100))%10 == 0)
		price = price+'0';
	if(discount == 1)
		price += '&nbsp;(<span style="color: #d00089;">-20%</span>)';
	document.getElementById('t_price').innerHTML = price;
	document.getElementById('t_size').innerHTML = Math.round(ch_sz*100)/100;
	document.getElementById('t_duration').innerHTML = modifier_duration(ch_dr);
	return true;
}
function modifier_duration(duration)
{
	var out = '';
	var num_mins = Math.floor(duration / 60);
	if(num_mins == 0)
		out +='00:';
	else if(num_mins < 10)
		out += '0'+num_mins+':';
	else
		out += num_mins+':';
	tmp = duration - (num_mins * 60);

	var num_secs = tmp;
	if(num_secs < 10)
		num_secs = '0'+num_secs;
	out += num_secs;
	return out;
}