flags/shifts(?) help

i recently discovered knytt stories and got right into making my own levels. right now i am making a level that requires juni to find a key and return to unlock a door. if you go to where the door is locked and juni doesn't have the key, the man next to the building says, "oh dear, i've lost the key to my store again." and his wife says, "sigh, my husband is always losing things." or something like that.

after finding the key and returning, before unlocking the door and winning, i would like to change what the man and his wife say to juni, to thank juni for finding the key. can this be done by using flags or whatever? i've only just started and the only thing that doesn't fully make sense to me is flags . the only other way i can think of is placing a shift on the same tile as the key and redrawing the entire world to change what they say.

any help would be greatly appreciated!

At position 1 place the lost key speech.
One square above, place the other speech and a warp object.

Here's what to put in the ini:
[position 1]
Flag(A)=Power8 (9 if yellow, 10 if blue, 11 if purple)
FlagWarpY(A)=-1

[one square above]
WarpY(L)=1 (R if you exit right, U if up, D if down)

At position 1 place the lost key speech.
One square above, place the other speech and a warp object.

Here's what to put in the ini:
[position 1]
Flag(A)=Power8 (9 if yellow, 10 if blue, 11 if purple)
FlagWarpY(A)=-1

[one square above]
WarpY(L)=1 (R if you exit right, U if up, D if down)

that worked, thank you so much.