HELP with PHP email form

Here is the code I have in my flash

System.useCodepage = true;
send_btn.onRelease = function() {
my_vars = new LoadVars();
my_vars.sender = email_box.text;
my_vars.subject = sbject_box.text;
my_vars.message = message_box.text;
if (my_vars.sender != “” and my_vars.subject != “” and my_vars.message != “”) {
} else {
my_vars.onLoad = function() {
email_box.onSetFocus = subject_box.onSetFocus=message_box.onSetFocus=function () {
if (error_clip._currentframe != 1) {

I need help figuring out how to add the PHP part, I have no idea about how to script it. I looked over some tutorials but I just don’t understand it. I got this code from when I was in college, I used it before but I can’t find the original PHPcode I used. It’s for my website, just a simple email form with a name, email, and message

can you help me out please?