Can posted input values on onbegin of ajax.beginform be modified? I have to modify values of some of the input fields after the form is submitted.
onbegin
ajax.beginform
You're having this issue because funBegin is called after the form data has been serialized. From MSDN:
funBegin
AjaxOptions.OnBegin Property: Gets or sets the name of the JavaScript function to call immediately before the page is updated.
I suggest you write your own submit handler: