if(isset($_POST)){
    
    $id = getPost("id");
    $id_client = getPost("id_client");
    $date = getPost("date");
    $inter = getPost("inter");
    $tech = getPost("tech");
    $comm = getPost("comm");
    $temps = getPost("temps");

  if($id){
  // Mise à jour via un UPDATE
    $sql_inter = "UPDATE inter
                  SET date = '$date'
                       , inter = '$inter'
                       , tech =  '$tech'
                       , comm =  '$comm'
                       , temps = '$temps'
                  WHERE id ='$id' ";
    $requete = mysql_query($sql_inter) or die( mysql_error()."<br>REQUETE:<pre>".$sql_inter."</pre>");

  }else{
   // Création nouveau ( INSERT )
      $sql_inter = "INSERT  INTO inter
                 (id_client, date, inter, tech, comm, temps)
                VALUES ('$id_client', '$date','$inter', '$tech', '$comm', '$temps')";
    $requete = mysql_query($sql_inter) or die( mysql_error()."<br>REQUETE:<pre>".$sql_inter."</pre>");
  }

{
   // Création nouveau ( INSERT )
      $sql_inter = "INSERT  INTO inter
                 (id_client, date, inter, tech, comm, temps)
                VALUES ('$id_client', '$date','$inter', '$tech', '$comm', '$temps')";
    $requete = mysql_query($sql_inter) or die( mysql_error()."<br>REQUETE:<pre>".$sql_inter."</pre>");
  }

CREATE TABLE IF NOT EXISTS `client_tb` (
  `id` smallint(5) NOT NULL,
  `nom_e` varchar(30) NOT NULL,
  `nom_cl` varchar(30) NOT NULL,
  `fixe` varchar(20) NOT NULL,
  `fonc` varchar(30) NOT NULL,
  `civ` varchar(20) NOT NULL,
  `groupe` varchar(20) NOT NULL,
  `contrat` varchar(20) NOT NULL,
  `fax` varchar(20) NOT NULL,
  `mob` varchar(20) NOT NULL,
  `mail` varchar(30) NOT NULL,
  `web` varchar(30) NOT NULL,
  `adr` varchar(30) NOT NULL,
  `ville` varchar(30) NOT NULL,
  `cp` char(5) NOT NULL,
  `infos` longblob NOT NULL

CREATE TABLE IF NOT EXISTS `inter` (
  `id` smallint(5) NOT NULL,
  `id_client` smallint(5) NOT NULL,
  `date` date NOT NULL,
  `inter` varchar(20) NOT NULL,
  `tech` varchar(20) NOT NULL,
  `comm` text NOT NULL,
  `temps` decimal(10,0) NOT NULL
) ENGINE=InnoDB DEFAULT CHARSET=latin1;

ALTER TABLE `client_tb`
  ADD PRIMARY KEY (`id`);

ALTER TABLE `inter`
  ADD PRIMARY KEY (`id`),
  ADD KEY `id_client` (`id_client`);

ALTER TABLE `client_tb`
  MODIFY `id` smallint(5) NOT NULL AUTO_INCREMENT,AUTO_INCREMENT=3;

ALTER TABLE `inter`
  MODIFY `id` smallint(5) NOT NULL AUTO_INCREMENT;

ALTER TABLE `inter`
  ADD CONSTRAINT `inter_ibfk_1` FOREIGN KEY (`id_client`) REFERENCES `client_tb` (`id`) ON DELETE CASCADE ON UPDATE CASCADE;

echo '<td><a href=[u]"[/u]inter.php?id='.$ligne['id'].'">'.$value.'</a></td>';

<table id="rec">
   <?php
    $NbrCol = 6;
     if($resulta){
      echo "<th>N°</th><th>Date</th><th>Type d'inter</th><th>Tech</th><th>Commentaire</th><th>Temps</th>";
      while($ligne=mysql_fetch_assoc($resulta)) {
       echo "<tr>";
       foreach($ligne as $value){
       [u] echo'<td><a href=inter.php?id='.$ligne['id'].'">'.$value.'</a></td>';[/u]