Probléme avec le header

<?php
class Chat {
	function __construct() {
		$this->link = mysql_connect("sql.free.fr","xxxx","yyyy") or die("mince");
		mysql_select_db("cendrine_jalu",$this->link) or die("flute");
	}
	
	function AjouteUser($user,$mdp) {
		//echo "INSERT INTO utilisateur(nom,password) VALUES ('$user','$mdp')";
		$contenu = mysql_query("INSERT INTO utilisateur(nom,password) VALUES ('$user','$mdp')",$this->link);
	}
	
	function message($message) {
		//echo "INSERT INTO dialogue (message) VALUES ('$message')";
		$message=addslashes ($message);
		$message = mysql_query("INSERT INTO dialogue (message) VALUES ('$message');",$this->link);
	}
	
	function connecte($user) {
		$connecte = mysql_query("INSERT INTO dialogue (utilisateur) VALUES ('$user')",$this->link);
	}
	
	function recup() {
		//echo "SELECT * FROM dialogue ORDER BY id DESC LIMIT 0 , 10";
		$result = mysql_query("SELECT * FROM dialogue ORDER BY id ASC LIMIT 0 , 10");
		while ($recup=mysql_fetch_object($result)) {
		echo "<br />";
		echo $recup->utilisateur.$_SESSION['user']." dit : ";
		echo $recup->message." ";
		echo $recup->date." ";
		echo "<br />";
		}
	}
	
	function smiley() {
		$smil= ':-)';
		$smil = str_replace(':-)' ,'<img src="rire.png">',$smil);
		/*echo $smil;*/
	}
}
?>