Correct spelling mistakes.

code/botlib/be_ai_chat.c

@@ -553,11 +553,11 @@ void StringReplaceWords(char *string, char *synonym, char *replacement)
 
 	//find the synonym in the string
 	str = StringContainsWord(string, synonym, qfalse);
-	//if the synonym occured in the string
+	//if the synonym occurred in the string
 	while(str)
 	{
 		//if the synonym isn't part of the replacement which is already in the string
-		//usefull for abreviations
+		//useful for abreviations
 		str2 = StringContainsWord(string, replacement, qfalse);
 		while(str2)
 		{