function fillSubcategoryComboBox(cbx, data)
{
	var options = data.split(",");

	if(options.length < 2) {
		addSelectOption(cbx, 'No categories', 0, '');
	} else {
		addSelectOption(cbx, 'Select a category', 0, '');
		for(var i = 0; i < options.length / 2; i++) {
			addSelectOption(cbx,
				options[i * 2],
				options[i * 2 + 1],
				'');
		}
	}
}

function updateSubcategoryCombo(id)
{
	var oAjax = new clsAjax();
	oAjax.url = '../ajax/ajax_ccategory.php';
	oAjax.method = 'POST';
	oAjax.addPostField('id', id);
	oAjax.fetchData();
	var data = oAjax.responseText;

	deleteSelectOptions('subcategory');
	fillSubcategoryComboBox('subcategory', data);
}