newbie question (forms)

I have just recently installed apache and php into my system (win98). The system test is ok....(showing php pages) Now for the question... I've created a form.. (rather cut and paste a form). This form works online I have tested it myself.. but locally it gives me an error.. When my php page loads it tells me "Notice: Undefined variable" at line whatever.. etc.. So what I've done it tested it online to see if it's the code...(full knowing that code works..since it's a cut out from a tutorial showing it's samples).. and it does work.. So the question is .. is there anything missing from my local server ??? Elvin