<?php
  if (isset($_POST["search"])) {

    //include database connection

 $word = mysql_real_escape_string($_POST["search"]);
 $word = htmlentities($word);

 $sql = ("SELECT task_id, task_date FROM customer JOIN task ON customer.id = task.customer_id WHERE mobil = $word ORDER BY task_date DESC LIMIT 0, 10");

$results = mysql_query($sql);
 if (mysql_num_rows($results)==0) {
  echo $word, " text bla";
}else {
  echo $word, " text bla bla";
   while ($row = mysql_fetch_assoc($results)) {
    echo '<pre>', print_r($row), '<pre>';
   }
  }
}?>