My website is using charset iso 8859 1
when user post
If you are trying to go to UTF8 after you are already using another encoding, try these steps:
Run ALTER TABLE tablename CONVERT TO CHARACTER SET UTF8 on your tables
Configure MySQL to default to UTF8 or just run the SET NAMES UTF8 query once you establish a database connection. You only need to run it once per connection since it sets the connection to UTF8.
Output a UTF8 header before delivering content to the browser. header('Content-Type: text/html; charset=utf-8');
Include the UTF8 content-type meta tag on your page. meta http-equiv="Content-Type" content="text/html; charset=utf-8"
If you do all those steps, everything should work fine.