sessions and arrays

I have a registration form that does a check on required values and displays error messages on the form. If a value is entered correctly I save it as a session. I am having problems saving an array in the session though. No matter how many values I enter it I can only echo two values and count produces a number 1 every time. The script is at http://www.atlantanites.com/join/ If you go there and select any number of values from the "Select the types of music you prefer" section and press enter the values you entered should be diplayed on the bottom of the page. I have echo statements for six values and the very last value is the count. Does anyone know what I am doing wrong, and how I can get the array to work properly. It stored the whole value of the array in mysql before I set up the check and used sessions. Now it will only enter one value. Brett