How to dynamically change content in HTML based on php database values?

I have this web based app with PHP (mysql) backend. I have a page to enter the grades and position received in a particular event. I need the page to show the checkboxes (for the grades) only if they have not been entered before. So I have this column P1 in my database and if this is NULL i need to show the checkboxes.

This is what i have on the php side

<?php
 $PID = (int)$_GET['PID'];
    $con = new mysqli("localhost","my_user","my_password",'events');
    $result = $con->query("SELECT * FROM eventlist WHERE Eid=$PID");
    global $output;
    $row =  $result->fetch_assoc();
    echo '<h1>'.$row["Ename"].'</h1>';
    if($row["P1"]==NULL)

  ?>

and what i need to be displayed in P1 is NULL is as follows

<h2>Slot 1</h2>
        <h3>Enter Result</h3>
        <div id="c1" class="radio">
          <label><input type="radio" name="opt1radio" value=30>First</label>

          <label><input type="radio" name="opt1radio" value=20>Second</label>

          <label><input type="radio" name="opt1radio" value=10>Third</label>
        </div>

       <h3>Enter Grade</h3>  
       <div id="c2" class="radio">
          <label><input type="radio" name="opt2radio" value=5>A</label>

          <label><input type="radio" name="opt2radio" value=4>B</label>

          <label><input type="radio" name="opt2radio" value=3>C</label>

          <label><input type="radio" name="opt2radio" value=2>D</label>

           <label><input type="radio" name="opt2radio" value=0>DQ</label>
        </div>
        <div id="submit">

          <button onclick="myFunction()" type="button" class="btn btn-success">Submit</button>
        </div>

How can i do this without putting echo in each and every HTML line.