返回错误的表单时，在Rails中重新填充选择选项时出现问题

I have a form with 2 select options in it -- frequency and duration. When there are errors with the form, and it is returned to the browser, the select options are not re-populated with the selections the user made even though the returned values for those fields match the values of options in the selects. Also, when the form is returned, these fields are not marked as having errors even though their values are blank.I have a form with 2 select options in it -- fr