<select id="Grouping_662066" class="productSelectInput" name="AddToCart_Grouping" onchange="DrawProduct(36331,662066,this.value,'',true);">
</select>

var example = $('#some-id');

    $(example).mousedown(function() {
            $(this).css('width','400px');
    });
    $(example).blur(function({
            $(this).css('width','200px');
    });
    $(example).change(function() {
            $(this).css('width','200px');
    });