wifi error: xivelyclient.put returned -1

I am trying connect my Arduino Uno to Xively using wifi and DHT11 (temp and humidity sensor). I have tried many times but getting the following error xivelyclient.put returned -1 . What is wrong in my code

/*
##Xively WiFi Sensor Tutorial##
This sketch is designed to take sensors (from photocell) and upload the values to Xively
at consistant intervals. At the same time it gets a setable value from Xively to adjust the brigthness
of an LED. This sketch is reusable and can be adapted for use with many different sensors.
Derived from Xively Ardino Sensor Client by Sam Mulube.
 
By Calum Barnes 3-4-2013
BSD 3-Clause License - [http://opensource.org/licenses/BSD-3-Clause]
Copyright (c) 2013 Calum Barnes
*/
#include <SPI.h>
#include <WiFi.h>
#include "HttpClient.h"
#include "Xively.h"
#include "DHT.h"


#define DHTPIN 2
#define DHTTYPE DHT11

DHT dht(DHTPIN, DHTTYPE);

char ssid[] = "enigma"; //  your network SSID (name) 
char pass[] = "1234567890";    // your network password (use for WPA, or use as key for WEP)
int keyIndex = 0;            // your network key Index number (needed only for WEP)

int status = WL_IDLE_STATUS;

// Your Xively key to let you upload data
char xivelyKey[] = "my xively api";
//your xively feed ID
#define xivelyFeed my xively feed no
//datastreams
char sensorhID[] = "Humidity";
char sensortID[] = "Temperature";

// Analog pin which we're monitoring (0 and 1 are used by the Ethernet shield)
//#define sensorPin A2
//led connected pin
//#define ledPin 9

// Define the strings for our datastream IDs
XivelyDatastream datastreams[] = {
  XivelyDatastream(sensorhID, strlen(sensorhID), DATASTREAM_FLOAT),
  XivelyDatastream(sensortID, strlen(sensortID), DATASTREAM_FLOAT),
};
// Finally, wrap the datastreams into a feed
XivelyFeed feed(xivelyFeed, datastreams, 2 /* number of datastreams */);

WiFiClient client;
XivelyClient xivelyclient(client);

void printWifiStatus() {
  // print the SSID of the network you're attached to:
  Serial.print("SSID: ");
  Serial.println(WiFi.SSID());

  // print your WiFi shield's IP address:
  IPAddress ip = WiFi.localIP();
  Serial.print("IP Address: ");
  Serial.println(ip);

  // print the received signal strength:
  long rssi = WiFi.RSSI();
  Serial.print("signal strength (RSSI):");
  Serial.print(rssi);
  Serial.println(" dBm \n");
}
void setup() {
  // put your setup code here, to run once:
  Serial.begin(9600);
  //pin setup
 // pinMode(sensorPin, INPUT);
 //pinMode(ledPin, OUTPUT);
   Serial.println("DHTxx test!");
 
  dht.begin();
  
  Serial.println("Starting single datastream upload to Xively...");
  Serial.println();

  // attempt to connect to Wifi network:
  while ( status != WL_CONNECTED) { 
    Serial.print("Attempting to connect to SSID: ");
    Serial.println(ssid);
    status = WiFi.begin(ssid, keyIndex, pass);
    // wait 10 seconds for connection:
    delay(10000);
  } 
  Serial.println("Connected to wifi");
  printWifiStatus();
}

void loop() {
  //adjust LED level. set from Xively
  /*int getReturn = xivelyclient.get(feed, xivelyKey);    //get data from xively
  if(getReturn > 0){
    Serial.println("LED Datastream");
    Serial.println(feed[1]);
  }else Serial.println("HTTP Error");
  
  */
  int h = dht.readHumidity();
  int t = dht.readTemperature();

  // check if returns are valid, if they are NaN (not a number) then something went wrong!
  if (isnan(t) || isnan(h)) {
    Serial.println("Failed to read from DHT");
  } else {
    Serial.print("Humidity: "); 
    Serial.print(h);
    Serial.print(" %\t");
    Serial.print("Temperature: "); 
    Serial.print(t);
    Serial.println(" *C");
  }
  /*
  //write value to LED - change brightness
  int level = feed[1].getFloat();
  if(level < 0){
    level = 0;
  }else if(level > 255){
    level = 255;
  }
  //actually write the value
  digitalWrite(ledPin, level);
 
///////////////////////////////////////////////////////
*/
  //read sensor values
 // int sensorValue = analogRead(sensorPin);
  datastreams[0].setFloat(h);
  datastreams[1].setFloat(t);
  //print the sensor valye
  Serial.print("Read sensor value ");
  Serial.println(datastreams[0].getFloat());
Serial.println(datastreams[1].getFloat());
  //send value to xively
  Serial.println("Uploading it to Xively");
  int ret = xivelyclient.put(feed, xivelyKey);
  //return message
  Serial.print("xivelyclient.put returned ");
  Serial.println(ret);
  Serial.println("");
  
  
  //delay between calls
  delay(15000);
}

Please help.