Formulaire de contact ne marche pas

<?php

$sendTo = "mon adresse email";
//Type your Site Name
$siteName = "Natura furesta";

$contact_name = $_POST['nam'];
$contact_email = $_POST['email'];
$contact_subject = $_POST['sujet'];
$contact_message = $_POST['message'];

if( $contact_name == true ) {
	$sender = $contact_email;
	$receiver = $emailAddress;
	$client_ip = $_SERVER['REMOTE_ADDR'];

	$email_body = "The Name Of The Sender: $contact_name \nEmail: $sender \n\nSubject: $contact_subject
\n\nMessage: \n\n$contact_message \n\nIP ADDRESS: $client_ip \n\n$siteName";

	$emailAutoReply = "Hi $contact_name, \n\nWe have just received your E-Mail. We will get
in touch in a few days. Thank you!  \n\n$siteName ";

	$extra = "From: $sender\r\n" . "Reply-To: $sender \r\n" . "X-Mailer: PHP/" . phpversion();
	$autoReply = "From: $receiver\r\n" . "Reply-To: $receiver \r\n" . "X-Mailer: PHP/" . phpversion();

	mail( $sender, "Auto Reply: $contact_subject", $emailAutoReply, $autoReply );

	if( mail( $receiver, "New E-Mail - $contact_subject", $email_body, $extra ) ) {
		echo "success=yes";
	} else {
		echo "success=no";
	}
}
?>

function clearField()
{
    txtField1.text = label1;
    txtField2.text = label2;
    txtField3.text = label3;
    txtField4.text = label4;
    txtField5.text = label5;
    Selection.setFocus("_focus");
} // End of the function
label1 = "Nom";
label2 = "E-mail";
label3 = "Téléphone";
label4 = "Sujet";
label5 = "Message";
countField = 5;
clearField();
var arrayLabel = new Array();
for (i = 1; i < countField + 1; i++)
{
    txtField = this["txtField" + i];
    txtField.index = i;
    arrayLabel[i] = this["label" + i];
    txtField.tabIndex = i;
    txtField.onSetFocus = function ()
    {
        if (this.text == arrayLabel[this.index])
        {
            this.text = "";
        } // end if
    };
    txtField.onKillFocus = function ()
    {
        if (this.text == "")
        {
            this.text = arrayLabel[this.index];
        } // end if
    };
} // end of for
btnClear.onRollOver = function ()
{
    this.gotoAndPlay("over");
};
btnClear.onRollOut = btnClear.onReleaseOutside = function ()
{
    this.gotoAndPlay("out");
};
btnClear.onRelease = function ()
{
    clearField();
};
btnSubmit.onRollOver = function ()
{
    this.gotoAndPlay("over");
};
btnSubmit.onRollOut = btnSubmit.onReleaseOutside = function ()
{
    this.gotoAndPlay("out");
};
btnSubmit.onRelease = function ()
{
    if (_parent.contactform.txtField1.text == label1 || _parent.contactform.txtField2.text == label2 || _parent.contactform.txtField3.text == label3 || _parent.contactform.txtField4.text == label4 || _parent.contactform.txtField5.text == label5)
    {
        gotoAndStop(3);
    }
    else
    {
        _parent.contactform.loadVariables("email.php", "POST");
        gotoAndStop(2);
    } // end else if
};
stop ();