can't run php files

[KGH]

I have installed xampp in which i could successfully run index.php,but if i run other files (.php files only)it will automatically leads to index.php only.Why it is so?Please help me.

Thank you.

[thescientist]

so if you view fileA.php in your browser, you always only see the contents of index.php in your browser? you didn't change your hosts file or anything?

[KGH]

Yes sir,I have admin folder in which index.php,login_success.php and logout.php files r there.In index.php,it checks for username and password.If both are correct it will goto login_success.php which is not happening.Whenever correct username and password are entered it will open index.php only allows us to enter username and password only.Not getting what s happening.I will paste the code.Please check it.

Thanks in advance..

index.php

login_success.php

logout.php