Unable to load my first opencv file

edit

 $ g++ `pkg-config --libs --cflags opencv` -o cv2 cv2.cpp

/tmp/ccuiICVX.o: In function `main':
cv2.cpp:(.text+0x23): undefined reference to `cvLoadImage'
cv2.cpp:(.text+0x36): undefined reference to `cvNamedWindow'
cv2.cpp:(.text+0x47): undefined reference to `cvShowImage'
cv2.cpp:(.text+0x51): undefined reference to `cvWaitKey'
cv2.cpp:(.text+0x5d): undefined reference to `cvReleaseImage'
cv2.cpp:(.text+0x67): undefined reference to `cvDestroyWindow'
collect2: error: ld returned 1 exit status

Can anyone please help me to fix this problem?