Answer 1

There are two minor issues.
#1 You forgot the script tag
#2 you misspelled your function in the script.

Answer 2

Yousuf Arman

There is nothing wrong, you are just not calling the function. So call function to get alert

Answer 3

Yousuf Arman

You called function on click event but you have missed opening script tag.

Please after changing anything in code, verify what changes you have done