please help me with my applet

hi, i'm quite beginner in programming java, morover i'm from poland and it's sometimes difficult for me to understand u, so could write respetively...

The problem, is that i have an applet and a visitor of my site have to fill data with name age etc, when there is no age, or the ThextField has too much signs, (>3) there should appear an error window informing that something is wrong. I suppose it shulod be dialog window, but it's constructor has a variable Frame on the first place, so what should i put there?
If there is somebody, who could help me, i could show my simple project only with few personal data to make all simplest for u. I attach the file, my email is fenders@interia.pl Please help me, here in Poland there is really few forums and people interested in java.

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