My helloworld program doesn't compile

[Polar]

I'm new to Pascal and I'm learning it using the Free Pascal compiler. I thought of starting with a helloworld program so I wrote this program:

Program helloworld ;

Begin

writeln ('Hello World') ;
readln ;

End.

The program compiled with no problems. Then I thought of adding a variable so I wrote this program:

Program helloworld ;

var

x : integer ;

Begin

x := 1 ;

writeln ('Hello World') ;
readln ;

End.

The program didn't compile and I got an error message. I don't understand why I simply added a variable. What should I do exactly?