What's the problem in my code 'Shafra'?

Question

I want to make button when I click on it value 'a' appear in textarea in HTML web.

Answer 1

I change it but there is the same problem

Answer 2

thanks very much for your answer

Answer 3

make it public for us

Answer 4

ok

Answer 5

document.getElementById in the end is Id not Ld

Answer 6

Id with big i