finally i could solve my problem. Now I know that mysql  dosen't use sequences.
but Oracle and PostgreSQL do.
I should change my toplink configuration. Is there any idea or instruction?
I eliminated @GeneratedValue from my code and my program works without any error  :D.
but this solution dosent make me satisfy because my program is damaged and this is not exactly that i wanted?
please help rebuilt my persistence.xml with new toplink configuration.