ajax - why error function is invoked when form data is submitted to google forms? -

i using jquery ajax post form data google forms. every thing works fine instead of done function fail function invoked ready state 4, status code 404, status text error. form data inserted successfully. in nettabs says 200 ok. can tell me why invokes fail function?

here's code:

var params = { "entry.870461494" : $('#name').val(), "entry.1837540694":$('#email').val(), "entry.794973559" : $('#cname').val(), "entry.1682659266" : $('#cnumber').val(), "entry.1004228063" : $('#city').val(), "entry.874570127" : $('#interested_in').val(), "entry.1619445424" : $('#bcategory').val().join() }   $.ajax({ url : "https://docs.google.com/a/<company-name>/forms/d/<key>/formresponse", data: params, type : "post", datatype: "xml" })   .done(function( msg ) {     alert( "saved google docs: " + msg ); }) .fail(function( msg ) {     alert( json.stringify(msg) ); });