diff --git a/dtmf-decoder.py b/dtmf-decoder.py
index 709d271..e85dcfa 100644
--- a/dtmf-decoder.py
+++ b/dtmf-decoder.py
@@ -3,10 +3,21 @@
 The wave file is split into bins and each bin is analyzed
 for all the DTMF frequencies. The method run() will return a numeric
 representation of the DTMF tone.
+
+USAGE:
+python dtmf-decoder.py filename
+
+Will decode and print the dtmf tones found in the wav file "filename"
+
+Example:
+python dtmf-decoder.py dtmf.wav
+
 '''
 import wave
 import struct
 import math
+import sys
+
 class pygoertzel_dtmf:
     def __init__(self, samplerate):
         self.samplerate = samplerate
@@ -93,7 +104,7 @@ def run(self, sample):
         return self.__get_number(freqs)
 if __name__ == '__main__':
     # load wav file
-    wav = wave.open('/home/michael/Downloads/dtmf.wav', 'r')
+    wav = wave.open(sys.argv[1], 'r')
     (nchannels, sampwidth, framerate, nframes, comptype, compname) = wav.getparams()
     frames = wav.readframes(nframes * nchannels)
     # convert wave file to array of integers