连接功能与PHP中的按钮

I have function to select all the data in my database with SELECT, and also made a form where I create a button for searching data in database by name, last name and id number, but I cant connect the button with my function to show me the data that I am searching for.

I think that I must create a event on button to show me the searched data.

I will show you my code for function:

public function findData ($id,$table){

    $sql = "SELECT `name`, `lastname`, `id_number` FROM `members`
    WHERE `name` LIKE '%".$word."%'
    OR `lastname` LIKE '%".$word."%'
    OR `id_number` LIKE '%".$word."%';";
    $q     = $this->conn->query($sql) or die("failed!");
    while($r = $q->fetch(PDO::FETCH_ASSOC)){
        $data[]=$r;
    }
}

And here I declare

 if(isset($_GET['find_id'])){
if($obj->findData($_GET['find_id'],"members"))

Please help me what to do to connect the function the button

This is my form

<form action="user.php" method="get">
<h4>Име</h4> <textarea cols="10" rows="1" name="find_id"></textarea>
  <h4>Презиме <h4> <textarea cols="10" rows="1" name="find_id"></textarea>
  <h4>Матичен број <h4> <textarea cols="10" rows="1" name="find_id"></textarea>
 <input type="submit" value="Submit"  name="find_id"></form>

Please try this

   if(isset($_GET['find_id'])){
     //call your function here 
      }

Your HTML file

  <form action="connect.php" method="get">
 <input type="submit" value="Submit"      name="find_id"></form>

Or use jQuery using ajax .