Feedback doesn't show message

What are you trying to achieve?:
I want my participants to get a feedback when they type the key answer. I used the code suggested in the posts of this group. In particular:

if not key_resp_5.keys :
    msg="Failed to respond"
elif resp.corr:#stored on last run routine
    msg="Correct! RT=%.3f" %(resp.rt)
else:
    msg="Oops! That was wrong"

These are inserted in the “begin routine”, after the key response

What specifically went wrong when you tried that?:
It doesn’t give me an error message but it simply doesn’t show any message.

Thanks for helping me!

What do you attempt to do with the msg variable to display it?