I have written a small script that will assist you into using communication between Flash and PHP to write to a mySQL database. The task is simple, verify the contents of the fields in flash and then send the information to PHP who then writes the information into the database.

ActionScript:
  1. var submitListener:Object = new Object();
  2. submitListener.click = function(evt:Object) {
  3.    try {
  4.       checkForm();
  5.    }
  6.    catch(e) {
  7.       result_ta.text = e.toString();
  8.       return;
  9.    }
  10.    var result_lv:LoadVars = new LoadVars();
  11.    result_lv.onLoad = function(success:Boolean) {
  12.       if (success) {
  13.          trace("THE ERROR = " + result_lv.error);
  14.          trace(unescape(result_lv.toString()));
  15.          if (result_lv.error != undefined) {
  16.             result_ta.text = result_lv.error;
  17.          }else{
  18.             result_ta.text = "Wrote to DB: \n";
  19.             result_ta.text += "First Name = " + result_lv.fname + "\n";
  20.             result_ta.text += "Last Name = " + result_lv.lname + "\n";
  21.             result_ta.text += "Age Name = " + result_lv.age + "\n";
  22.             result_ta.text += "Total Records = <b>" + result_lv.nuRows + "</b>";
  23.          }
  24.        } else {
  25.          result_ta.text = "Error connecting to server.";
  26.        }
  27.    }
  28.    var send_lv:LoadVars = new LoadVars();
  29.    send_lv.fname = fn_tfl.text;
  30.    send_lv.lname = ln_tfl.text;
  31.    send_lv.age = age_tfl.text;
  32.    send_lv.sendAndLoad("path/to/your/php/file.php", result_lv, "POST");
  33. };
  34. submit_btn.addEventListener("click", submitListener);
  35. function checkForm() {
  36.    if (fn_tfl.text == undefined || fn_tfl.text.length < 1) {
  37.        throw new Error("First name is required");
  38.    }
  39.    if (ln_tfl.text == undefined || ln_tfl.text.length < 1) {
  40.       throw new Error ( "Last name is required");
  41.    }
  42.    if (age_tfl.text == undefined || age_tfl.text.length < 1) {
  43.       throw new Error ( "Age is required");
  44.    }
  45. }

This is the script used to create the tables and fields:

PHP:
  1. CREATE TABLE `users` (<br />
  2. `id` INT( 6 ) NOT NULL AUTO_INCREMENT PRIMARY KEY ,<br />
  3. `fname` VARCHAR( 15 ) NOT NULL ,<br />
  4. `lname` VARCHAR( 15 ) NOT NULL ,<br />
  5. `age` INT( 3 ) NOT NULL<br />
  6. ) ENGINE = MYISAM ;

Make sure you check the mySQL version on your server in case you encounter any errors.