ERROR ILLEGAL EXPRESSION

This pascal program should calculate net pay etc. Got it down to one error that says;
Payroll2.pas(40,33) Error: Illegal expression
Payroll2.pas(45,4) Fatal: There were 1 errors compiling module, stopping
Fatal: Compilation aborted
Error: /usr/bin/ppc386 returned an error exitcode (normal if you did not specify a source file to be compiled)

Any help would be appreciated.



Program Payroll2(input,output);
uses crt;
CONST
BasicRate=2350;
TaxRate=0.165;
VAR
Firstname:Array[1..6]of String;
Surname:Array[1..6]of String;
Overtime_Pay,GrossPay,Tax,Bonus,NetPay:Real;
Hoursworked,X:Integer;
Overtime_Rate:Real;
Begin
clrscr;
X:=0;
GrossPay:=0;
Tax:=0;
Overtime_Pay:=0;
NetPay:=0;
Bonus:=0;
FOR X:=1 TO 6 DO
begin
Writeln('Please enter your firstname,surname and hours worked');
Readln(Firstname[X],Surname[X],Hoursworked);
IF Hoursworked <= 40 THEN
Begin
Writeln('hours are 40 or less');
Writeln('test line #2');
//Overtime_Pay:=(Hoursworked-40)*(BasicRate*1.5);
//GrossPay:=(BasicRate*40)+Overtime_Pay;
//Tax:=GrossPay*TaxRate;
end;

IF Hoursworked <= 40 THEN
begin
Writeln('hours more than 40');
Bonus:=BasicRate*0.5;
end;
if Hoursworked > 40 THEN
Bonus:=BasicRate*0.2;
NetPay =(GrossPay+Bonus)-Tax;
Writeln(Firstname[X],Surname[X]);
Writeln('HAVE A NICE DAY!');
end;
Readln;
END.