[PHP] insert to table in php scripts

[Negin Nickparsa]

I have a code that i get the $_POST's result and then insert them in tables
of Mysql
it can run without error but it'll insert in the table twice and i don't
know why.
when I click the submit then with array_key_exists I go to if statement and
insert it.
i'll show the code if someone have time helping me.
cheers