Submitting a form using the SUBMIT method of a form not sent null parameters. If not I select a combobox value, this field does not send by SUBMIT method.
Attached is an example that you can found in ExtJS demos: http://dev.sencha.com/deploy/ext-4.1.../xml-form.html
And also a screenshot where you can see combobox field is not sent at Chrome console.
How I can force form submit sent all fields?