I am using prototype and I post the values via serialize and the data get there via ajax.request post without any issue; but the issue is when using multiple option style.
This multiple option styles are not required fields at all; but when they have values the values are passed to the server side without any issue but when clearing all the options the multiple select box return null value so the server does not receive the select box name or id and because of this the field is not updated to the database.
The is a big issue because if I want a multiple not required field even if the first option has a value -1 or 0 the multiple select list is lost and there is impossible to update the content to the database!
I will like this to be fixed in some way because I like chosen!!
Chosen doesn't do anything special to the form field it's replacing visually. You would parse the select field as you would any other select field. If you can you provide a fiddle showing this problem in action, maybe we can point you in the right direction.