What is wrong with these Codes!!!!???

Hello.. I made these three PHP files.. but I don't know where is the problem!!!! Login.php ---------> This will grab the UserName, Password and Serial fields by GET then compare them with the one in the database (After MD5 them) Activate.php ------> For the admin.. he can activate users account by entering the UserName in a filed inside "Activate.htm" and then UPDATE a value in the database to ACTIVATED Deactivate ----------> This will deactivate the account.. the same as the upper one.. Now.. The Login.php page is saying : Parse error: parse error in c:\apache\htdocs\user\login.php on line 20 The Activate.php page is saying : Warning: Supplied argument is not a valid MySQL-Link resource in c:\apache\htdocs\admin\activate.php on line 31 The Deactivate.php is saying the same as the Activate.php error. So I don't know where is the problem!!! everything is okay.. And there is no errors in the scripts.. so can you please take a look at them..maybe there is some falts.. I attached the THREE PHP files with the TWO HTM files for the activation (POST the UserName for the Activation and Deactivation) Also with the .sql file of the database Waiting your help please.. Regards..