You are getting the 'GetSkillLevel' errors because the function/procedure 'GetSkillLevel' isn't included in SRL 4. Below is the new way to do this...
SCAR Code:
GetSkillInfo(skillName: String, false);
This will return an integer so you could say...
SCAR Code:
writeln('' + IntToStr(GetSkillInfo('fishing',false));
But if you just wanted to say your skill in-game then there is a special method in Anit-Ban.scar called SayCurrentLevels(which: String). You could use this in a similar fashion...
SCAR Code:
SayCurrentLevels('fishing');
That will basically TypeSend your fishing level to the game... 
Keep posting in this thread for more help!