[lazarus] Pascal error message

[Shane Miller]

Here's the actual code I am having trouble with....

procedure THighLightAttributes.SetStyleFromInt(const Value: integer); 
begin 
  if (Value and $1)  = 0 then  Style:= [] 
else Style:= [fsBold]; 
  if (Value and $2) <> 0 then Style := Style + [fsItalic]; 

  if Value and $4 <> 0 then Style:= Style+[fsUnderline]; 
  if Value and $8 <> 0 then Style:= Style+[fsStrikeout]; 
end; 

Style is a TFontStyles (defined in Graphics.pp)
Any reason I am getting 
Error: Operator is nopt overloaded
on the line where is adds [fsItalic] to style?

Shane