upperCase to lowerCase

[Rolf Kocherhans]

Can anyone help me to rewrite the function below so that it changes 
upperCase to lowerCase.


This Function changes lowerCase to upperCase:

function upperCase whatStr
   repeat with charNum = 1 to the number of chars in whatStr
     put charToNum(char charNum of whatStr) into thisChar
     if thisChar >= 97 AND thisChar <= 122
     then put numToChar(thisChar - 32) into char charNum of whatStr
   end repeat
   return whatStr
end upperCase

TIA
Cheers
Rolf