Continuous Dial Tone Detection (java)

I have been asked to write an algorithm in Java to detect a continuous
dial tone.  Anyone have experience doing so?

I have looked into the Goertzel algorithm, but I am unable to
understand how I determine if I've encountered a dial tone by looking
at the algorithm's output.  For example:

 Sampling Rate = 8000
 N = 205
 Frequency = 941
 k = 24 and coeff = 1.4828667

 Relative magnitude squared = 131986.38
 Relative magnitude = 363.29929

What does that tell me?  Any help is much appreciated.  Does this tell
me a dial tone was detected or not?  If not (as I assume), what would
the output look like if it did in fact detect a continuous dial tone?

I used the code from
http://www.embedded.com/shared/printableArticle.jhtml;jsessionid=DTZUHZ5RVHHLUQSNDBECKH0CJUMEKJVN?articleID=9900722

Thank you,
-Elliot