Mysqli Prepared statement and $mysqli->affected_rows > 0

Hi All

I am a bit confused on how to add $mysqli->affected_rows > 0 to a Mysqli Prepared statement, any help would be more than appreciated.

<?php 
$mysqli = new mysqli('localhost', $username, $password, $db_name); 

/* check connection */ 
if (mysqli_connect_errno()) { 
printf("Connect failed: %s\n", mysqli_connect_error()); 
exit(); 
} 

if ($stmt = $mysqli->prepare("SELECT * FROM $tbl_name WHERE phone_number=?")) { 

/* Bind our params */ 
$stmt->bind_param('s', $prefixphone); 


$stmt->execute(); 


$stmt->close(); 

/* Error */ 
printf("Prepared Statement Error: %s\n", $mysqli->error); 

} 
if ($mysqli->affected_rows > 0){ 
echo 'something here.....'; 
} 

?>

The above trick did not work.... My prepared function without "if ($mysqli->affected_rows > 0)" does not return any errors by the way.

Thank you,

Ben