Haar- Cascade face detection OpenCv

I used the following code to detect a face using Haar cascade classifiers provided by OpenCv Python. But the faces are not detected and the square around the face is not drawn. How to solve this?

import cv2

index=raw_input("Enter the index No. : ")

cascPath = "haarcascade_frontalface_default.xml"
faceCascade = cv2.CascadeClassifier(cascPath)

cap = cv2.VideoCapture(0)

cont=0

while(True):
   # Capture frame-by-frame
   ret, frame = cap.read()

   # Our operations on the frame come here
   gray = cv2.cvtColor(frame, cv2.COLOR_BGR2GRAY)

   faces = faceCascade.detectMultiScale(
  gray,
  scaleFactor=1.1,
  minNeighbors=10,
  minSize=(30, 30),
  flags = cv2.cv.CV_HAAR_SCALE_IMAGE
  )

for (x, y, w, h) in faces:
    #cv2.rectangle(frame, (x, y), (x+w, y+h), (0, 255, 0), 2)
    cv2.rectangle(frame, (x, y), (x+w, y+h), (0, 255, 0), 2)


   # Display the resulting frame
  cv2.imshow('frame',frame)
  inpt=cv2.waitKey(1)

  if inpt & 0xFF == ord('q'):
    break

  elif inpt & 0xFF == ord('s') :

    #name='G:XCODRAIntegrated_v_01EigenFaceRecognizerimg2'+index+"."+(str(cont))+".png"
    name='IC_image\'+index+"."+(str(cont))+".png"
    resized = cv2.resize(gray,None,fx=200, fy=200, interpolation = cv2.INTER_AREA)
    img=cv2.equalizeHist(resized)

    cv2.imwrite(name,img)
    print cont
    cont+=1