STRTRAN() function doesn't update source string but returns result string.

lcMemo =  STRTRAN(MyTable.Methods,"QueryUnload","QueryUnloadHook")

>I have an SCX open as a table and am trying to replace the instance of the character expression "QueryUnload" WITH "QueryUnloadHook"
>
>I have tried:

>  STRTRAN(MyTable.Methods,"QueryUnload","QueryUnloadHook")
>
>  lcMemo = MyTable.Methods
>  STRTRAN(lcMemo,"QueryUnload","QueryUnloadHook"
>  REPLACE Methods WITH lcMemo, ;
>          ObjCode WITH SPACE(0) IN MyTable
>
>  lcMemo = MyTable.Methods
>  CHRTRAN(lcMemo,"QueryUnload","QueryUnloadHook")
>  REPLACE Methods WITH lcMemo, ;
>          ObjCode WITH SPACE(0) IN MyTable

>
>There is defintely an occurence of "QueryUnload" in the Methods memo field.
>
>What am I misunderstanding ?
>
>Cheers,
>Jamie