jQuery 设置checked="checked"无效，radio未选中。。

If in jQuery >= 1.6:

Use prop as seen here: .prop() vs .attr()

$itemVariantRowRadio.prop('checked', true);

If in jQuery < 1.6:

$itemVariantRowRadio.attr('checked', true);

http://stackoverflow.com/questions/6432246/radio-buttons-and-attrchecked-checked-does-not-work-in-ie7