I have a form that a user insert some input

form accept-charset='UTF-8' action="addcommentcheck.jsp" method="post" id="addcommentid">

and at addcommentcheck.jsp i do
But when i try to insert it to database the only thing that i insert is ????? When i show to the user the input i can see the correct input but when i insert to database i have the ??? What i am doing wrong?
Thank you very much

What collation is your database using?

how do i change the collation of my database? I want to change it to utf8_general_ci or to utf8_unicode_ci? What is the difference? Is there any command to change the database collation?

thank you very much