Membuat program ganti kata pada pascal

Program Ganti_Kata; Uses Crt;

Var Kata, Ganti, Pengganti : String; Pss, Pjg : Byte;

Begin Clrscr; Write; Write; ; readln ; Write; ; readln ; Write; ; readln ;

Pss := Pos ( , ); Insert ( , , ); Pss := Pos( , ); Pjg := Length( ); Delete ( , , );

Write;

Write ; Readln; End.

Tolong dong, pak guru cuman kasih clue nya begitu doang:(