[jQuery] ajax post data json - php receives only post data, no json

[mcologne]

hi...

i have a normal email form, where the user can send an email with some
data...

at first i send it with normal post (no dataType in jquery)... but it
was difficult to handle the returning messages from php, e.g.
validation messages or ok messages...

therefor i tried dataType json... like the code below... now i con
better handle the returning messages, but i wonder why i still get
single post data in php ($_POST['name'], $_POST['email)'] etc and NO
nested json!... is there something wrong with my data format?

in firebug i also see only single post data... no json format when
posting

best regards
m, cologne

##############################
$.ajax({
          type: "POST",
          url: "/mail/process.php5",
          data: {"name":name, "email":email, "message":message, "n":textmail,
"i":pic},
          dataType: "json",
          success: function(res) {
                  if(res.result == 1) {
                         $('#dialog').html("<p>WE SEND THE EMAIL" +
res.message + "</p>");
                 }
                 else if(res.result == 0) {
                       $('#dialog').html("<p>ERROR" + res.message + "</p>");
                 }