Drop Down List Populated from a MySQL Database

Hello!

I am a newbie to PHP-MySQL. I am trying to populate 2 drop down lists
from a MySQL DB. First drop down list(Build_Name) has building names and 2nd
one has dates(Pickup_Dates) . Once a User chooses both drop down lists lets say bldg 1 and
09/30/2004 it should display records if it has any in the database else we should be able
to add a record in the db.Any immediate help is highly appreciated.

These r my two tables...

CREATE TABLE Buildings (
Bldg_Name varchar(25) NOT NULL default '' PRIMARY KEY,
Driver_ID tinyint(2) NOT NULL default '0'
) TYPE=MyISAM;

CREATE TABLE order (
Order_ID INT(5) NOT NULL default 101,
Bldg_Name varchar(25) NOT NULL default '',
Pickup_Date date NOT NULL default '0000-00-00',
PRIMARY KEY (Order_ID,Delivery_Date,Bldg_Name)
) TYPE=MyISAM;


Thanks,
Sean