Is something wrong with this?

EVENT_SAY{
if($1- =~ "Hail"){
SAY("Hi $name this is the swimming pool. Did you already master [swimming]?")
}
if($1- =~ "swimming"){
SAY("Just tell me and ill make you [master swimming] instantly!")
}
if($1- =~ "master swimming"){
SAY("You have now mastered swimming!")
setskill 50("252")}
}
/*END of FILE Zone:cshome ID:7301 -- Swim_instructor */



there something wrong with the setskill 50("252")} command I want the person to master swimming so how do I do this?