Multiple Select select_tag in mobile populated options disappears when touched

.left.gap_right
  %label.select.control-label{:for => "appointment_reason_ids"} Reasons
  = select_tag("appointment[reason_ids][]", 
  options_for_select(Reason.option_list, f.object.reason_ids),  {:class => 
  'span5 multiselect', :multiple => :multiple})

I am using the multi-select feature in rails 3. The above code works fine on Laptop, but when used in mobile the populated options closes on touch. Is there any solution for this. Or any alternative way of using this.