I have retrieved the user's login, name, address and email from a separate MySQL database and have them stored in an array in php. How exactly do I use the Fill_In_Signup_Form hook to transfer these values into the sign up form so the user doesn't have to fill them in? Please explain slowly - I am a php noob. I read the manual but still didn't get it. Thanks for any help you can offer.
Why not just autocreate the users in aMember (with no purchases) from the data in your external database (export to .csv and one time import into aMember).. whatever mechanism you are using to retrieve them for your PHP array, just set the aMember cookie so they are automatically logged in (ie. no reason to register)
Thanks for your suggestion. However it won't apply in my particular case. Only a small number of the people in my database will want to register, and they need to choose whether to opt in. I do not want to register people except by their explicit action. I want those who opt in to enter their exiting user id and I then retrieve their existing data from my database. They only have to choose a password. I need to ensure that their amember user id is the same as their existing id, so I must set the value of user id, not allow them to enter it.