function onChangeSizes()
{
	var selectGender = document.getElementById('gender');
	var selectProduct = document.getElementById('product');
	var selectSize = document.getElementById('size');
	
	if(selectSize.length > 0)
	{
		for(var i = 0, end = selectSize.length; i < end; i++)
		{
			selectSize.remove(selectSize.options[i]);
		}
	}
	
	var option = document.createElement('option');
	option.selected = 'selected';
	option.value = 'all';
	option.innerHTML = 'Choose sizes';
	selectSize.appendChild(option);
	
	var optionGender = selectGender.options[selectGender.selectedIndex].value;
	var optionProduct = selectProduct.options[selectProduct.selectedIndex].value;
	
	if((optionGender != 'all') && (optionProduct != 'all'))
	{
		if(sizes[optionProduct])
		{
			for(var i = 0, end = sizes[optionProduct][optionGender].taglie.length; i < end; i++)
			{
				var option = document.createElement('option');
				option.value = sizes[optionProduct][optionGender].taglie[i];
				option.innerHTML = sizes[optionProduct][optionGender].taglie[i];
				selectSize.appendChild(option);
			}
		}
	}
}