JSON Library?

In Arduino how to use both json generator and parser library in a single sketch ?

While i use ,
#include <JsonGenerator.h>
#include <JsonParser.h>

It throws errors stating,

"ArduinoJsonParser\utility\jsmn.cpp.o: In function jsmn_parse(jsmn_parser*, char const*, jsmntok_t*, unsigned int)': C:\Users\Guna Qruize\Documents\Arduino\libraries\ArduinoJsonParser\utility/jsmn.cpp:135: multiple definition of jsmn_parse(jsmn_parser*, char const*, jsmntok_t*, unsigned int)'
ArduinoJson\JsonParser.cpp.o:C:\Users\Guna Qruize\Documents\Arduino\libraries\ArduinoJson/JsonParser/jsmn.cpp:135: first defined here
ArduinoJsonParser\utility\jsmn.cpp.o: In function jsmn_init(jsmn_parser*)': C:\Users\Guna Qruize\Documents\Arduino\libraries\ArduinoJsonParser\utility/jsmn.cpp:250: multiple definition of jsmn_init(jsmn_parser*)'
ArduinoJson\JsonParser.cpp.o:C:\Users\Guna Qruize\Documents\Arduino\libraries\ArduinoJson/JsonParser/jsmn.cpp:250: first defined here"