var gt_sort = 0;

function updateRadio (p_obj)
{
	if	(!p_obj.checked)	return;
	if	(gt_sort == p_obj.value)	return;
	gt_sort = p_obj.value;
	updateSelect1 ();
	updateSelect2 ();
	var span = getObj(gt_fields[2]);
	if	(span != null)
		span.innerHTML = gt_fields[(gt_sort == 0)? 3: 6] + ':';
	span = getObj(gt_fields[5]);
	if	(span != null)
		span.innerHTML = gt_fields[(gt_sort == 0)? 6: 3] + ':';
}

function updateSelect1 ()
{
	var sel1 = getObj(gt_fields[1]);
	if	(sel1 == null)
		return;

	truncSelect (sel1);

	sel1.options[0] = new Option('--- Select ---', '');
	var i;
	var chs = gt_choices[gt_sort];
	var len = chs.length;
	for (i = 0; i < len; i++)
	{
		sel1.options[i + 1] = new Option(chs[i][0], i + 1);
	}

	sel1.selectedIndex = 0;
}

function updateSelect2 ()
{
	var sel1 = getObj(gt_fields[1]);
	if	(sel1 == null)	return;
	var sel2 = getObj(gt_fields[4]);
	if	(sel2 == null)	return;
	var opts2 = sel2.options;

	var pd1_index = sel1.selectedIndex;
	pd1_index = sel1.options[pd1_index].value;

	var i;
	var j;
	truncSelect (sel2);
	opts2[0] = new Option ('--- Select ---', '');
	if	(pd1_index < 1)
	{
		sel2.disabled = true;
		return;
	}
	var chs = gt_choices[gt_sort];
	var chs2 = chs[pd1_index - 1];
	var len = chs2.length;
	if	(len < 4)
		opts2[0] = new Option(chs2[1], gt_links[chs2[2]]);
	else
	{
		for (i = 1, j = 1; j < len; i++, j += 2)
		{
			opts2[i] = new Option(chs2[j], gt_links[chs2[j + 1]]);
		}
	}

	sel2.disabled = false;
	sel2.selectedIndex = 0;
}

function gotoURL ()
{
	var l1 = gt_fields[(gt_sort == 0)? 3: 6];
	var l2 = gt_fields[(gt_sort == 0)? 6: 3];
	var sel1 = getObj(gt_fields[1]);
	if	(sel1 == null)	return false;
	var sel2 = getObj(gt_fields[4]);
	if	(sel2 == null)	return false;
	if	(sel1.selectedIndex < 1)
	{
		alert ('Please select ' + l1);
		return false;
	}
	var ind2 = sel2.selectedIndex;
	if	(ind2 < 0)
	{
		alert ('Please select ' + l2);
		return false;
	}
	var link = sel2.options[ind2].value;
	if	(link == '')
	{
		alert ('Please select ' + l2);
		return false;
	}
//	alert('document.' + gt_fields[0] + '.action = ' + link);
	eval('document.' + gt_fields[0] + '.action = link');

	return true;
}

function getObj (p_id)
{
	var obj = null;
	if	(document.getElementById)
		obj = document.getElementById(p_id);

	if	(obj == null)
		obj = eval('document.' + gt_fields[0] + '.' + p_id);

	return obj;
}

function truncSelect (p_pd)
{
	var i;
	var opts = p_pd.options;
	for (i = opts.length - 1; i > 0; i--)
	{
		opts[i] = null;
	}
}