how to solve problem accent in database mysql

Question

hi friends

how to do please

mysql doesn't accept accent ex:éàè.... 

this my script to connect in database  

<?php

$connection = mysqli_connect('localhost', 'root', '');

mysqli_set_charset('utf-8',$connection);

if (!$connection){

die("Database Connection Failed" . mysqli_error($connection));

}

$select_db = mysqli_select_db($connection, 'devhelp_db');

if (!$select_db){

die("Database Selection Failed" . mysqli_error($connection));

}

?>

it show me this error

Warning: mysqli_set_charset() expects parameter 1 to be mysqli, string given in C:\xampp\htdocs\devhelp\connectdb.php on line 4