too long

When click on search, the data displays, but when I click again, the data disappear. I know its a simple thing but I really cant figure it out. im trying to explain as much as i can.

Search Engine: <input type="text" name="search" placeholder="Enter keywords..." />
<input type="submit" name="search_product" value="Search now"/>


   </form>

 mysql_connect("localhost", "root", "");
    mysql_select_db("tutorial");


    if(empty($_GET['search'])){

        echo "No Search results";
    }   
    if(!empty($_GET['search'])){

    if (isset($_GET['search_product'])){

                 $search_value = $_GET['search'];

                  $query = "SELECT * FROM `blob` WHERE keyword LIKE '%$search_value%'";


              $run = mysql_query($query);

              while($row = mysql_fetch_array($run)){

                $name = $row['name'];
                $categorie = $row['categorie'];
                $lieu = $row['lieu'];
                $image = $row['image'];


                echo ("<div style='text-align:center;' style=width:300px; align='center';><h2><p>Nom du Produit: $name</h2> <strong>Categorie:</strong> $categorie <p><strong>Lieu:</strong> $lieu </p></p></div>");    
                echo "<div style='margin-left:630px;'>";?><?php echo"<img src=$image <height='150' width='150'>"?> <?php echo "</div>";
                echo "<hr/>";


              } 
    }

    }

Just echo the search data $search_value = $_GET['search'] After click on the search button again. If you don't get any data in $search_value then in query you will not find any of the data.

<?php
if(isset($_GET['search']) && !empty($_GET['search']) )
{
    $var = $_GET['search'];
    echo $var;//var_dump($var);
    echo '</br>';
}
if(isset($_GET['search']) && empty($_GET['search']) )
{
    echo "empty";
}
?>
<form action = "" method = "GET">
<input type="text" name="search" placeholder="Enter keywords..." />
<input type="submit" name="search_product" value="Search now"/>
</form>

I'm showing you a demo this may help you.