Using a href onclick to update div without reloading page?

Question

I used this existing question to help me out: HTML - Change\\Update page contents without refreshing\\reloading the page

The template-comparison.php file fetches the

Answer 1

$results = mysql_query("SELECT * FROM PresidentialCandidate WHERE  ID='$ID'");   
if( mysql_num_rows($results) > 0 )
{
   $row = mysql_fetch_array( $results );
   echo $row['ID'];
}

Replace with:

$sql = "SELECT * FROM PresidentialCandidate WHERE  ID='$ID'";
$result = $conn->query($sql);
if ($result->num_rows > 0) {
  $row = $result->fetch_assoc();
  echo $row['ID'];
}

Please don't mix both mysql_* & mysqli_* functions.