[Deff]

<script src="http://code.jquery.com/jquery-latest.js"></script>



<form class="variants" action="/cart">
<div>
<select name="dop_variant">
<option dv_id="54">Оригинальный</option>
<option dv_id="49" not="Синий,105">Китайский</option>
</select>
</div>

<select name="variant"   form="variants">
<option value="104" compare_price="222" price="111" class="option_var" v_dv_id="49">Красный</option>
<option value="105" compare_price="333" price="222" class="option_var" v_dv_id="54">Синий</option>
<option value="111" compare_price="666" price="555" class="option_var" v_dv_id="49">Зеленый</option>
</select>
<div class="clear"></div>
Акция! <strike>222</strike>
</br>
<span>111</span><i>руб</i>	
<div class="clear"></div>
<input type="submit" class="button" value="в корзину" data-result-text="добавлено"/>
</form>



<script>

 $(function() {

	// Выбор вариантов цены
	$('select[name=variant]').change(function() {
	//...................
	});


    //Работа с option
    $('select[name=dop_variant]').change(function(){
	var thsOpt = $(this).find('option:selected');
	var not=thsOpt.attr('not')
	$("select[name=variant]").find("option").removeAttr('disabled')
	if(not){  not=not.split(",")[1];
//alert(not)
	   var a=$("select[name=variant]").find("option[value='"+not+"']").attr('disabled',true);

	}
    });
 });
</script>