JSON Results offered to be saved

I'm new to JSON and I'm just wondering why every time I try to pass results as JSON, the browser (Firefox) always offers me to save it as a local file? Is that the behavior of JSON? I thought it would be like passing XML that the browser will only show it. I'm 开发者_如何学Gobuilding the JSON using PHP:

header('Content-Type: application/json');
$json = "{\n";
$json .= "  \"address\": \n";
$ctr = 0;
$numrows = mysql_num_rows($result);
while($row = mysql_fetch_array($result, MYSQL_ASSOC)){
        $json .= "    {\n";
    $json .= "     \"id\": \"". $row['id'] ."\",\n";
    $json .= "     \"lon\": \"". $row['lon'] ."\",\n";
    $json .= "     \"lat\": \"". $row['lat'] ."\",\n";
    $json .= "     \"road\": \"". $row['road'] ."\" \n";
    $json .= "    }";
    $ctr++;
    $json .= ($ctr < $numrows) ? ",\n" : "\n" ;
}
$json .= "}";
echo $json;

JSON is not XML of course. If you omit the Content-type header or set it to e.g. text/plain the browser will render it. However, the current content-type is correct. Install the JSONView extension to be able to see json in the browser instead of getting a download window.

Besides that, NEVER EVER BUILD JSON USING STRING FUNCTIONS. PHP has json_encode() which takes an object/array/.. and returns a valid JSON string. So your code should look like this:

header('Content-Type: application/json');
$rows = array();
while($row = mysql_fetch_array($result, MYSQL_ASSOC)){
    $rows[] = $row;
}
echo json_encode($rows);