clear() not working

[guriaregojo]

Hi, I think the clear is not working correctly. If I run this program, during the first execution "hey" appears and then "hello grace" appears ("hey" and "hello grace" do not superpose, "hello grace" substitutes "hey" which is what I want the program to do). However when the "clear screen block" is called in execution 1 then for execution 2 "hey" never appears on screen again and "Hello grace" remains on screen for the whole time (screen is not cleared). On the other hand if I remove the clear block the "hey" of execution 2 superposes with"hello grace".
Could you explain the correct way of using clear so as to have "hey" and "hello grace" appear one by one everytime for the 4 executions?
Thank you!!

[shaoziyang]

The range of paramter row is from 0 to 7, value 50 will out of buffer range and cause 022 error.

[guriaregojo]

That was it! I changed the row param to 0-7 and now everything is working normally.
Thank you so much