Swedish characters don't display on Iphone


i have recently created a homepage using PHP/SQL. The page contains swedish text with the characters “åäö”. To handle this I use the following line …

header(‘Content-Type: charset=utf-8’);

This works fine when the page is displayed on my PC laptop, PC desktop and Samsung tablet.
But on iphone åäö is replaced with question marks.

i have no idea how to solve this problem, so I would be grateful for any suggestions.

Regards Peter