List box question

I am new to this forum, and am not for sure if I am posting this in the right spot or not. I have a php code that fills a listbox with first names of people that are in my database. I was wondering if someone could help me to find out how do I get it to where when someone clicks on the first name of the person it shows their birthday and lastname under the listbox. I have a primary key and it is called ID, I have 3 fields called first, last, and bday. I was not sure how to set the item clicked to the url, but if I can do that then can't i just pull it back down and then essentially use php to select * from table where $name = name. I know I am probably going about this the totally wrong way but can someone help?

if you want to do this on the fly without reloading the page you need to use javascript, if you're talking about submitting a form then you can set the value of each selection to the id value and then pull back the bday and last name from the db based upon WHERE id = $id

I'm also new user ...
i need to assign each value at my list box to different page ..
Can you tell me how ?? plz

thnx