How do you convert casetts to cd.

You can use your computer to do it. Here's a tutorial showing you how to do it without having to buy much...

Converting audio cassette tapes to CD, MP3 and other digital formats

You'll need:

1) a cassette tape player with a headphone jack
2) a computer with a soundcard
3) the free "Audacity" software
4) 3.5mm (1/8-inch) male-male stereo audio cable (Though 3.5mm is a standard size, your own hardware may be different.) A six-foot cable can be found for about $5.00 at your local electronics store like Radio Shack.