17 & 18 please

In a script, the user is supposed to enter either a 'y' or 'n' in response to a prompt. The user's input is read into a character variable called "letter". The script will print "OK, continuing" if the user enters either a 'y' or "Y" or it will print "OK, halting" if the user enters a 'n' or 'N' or "Error" if the user enters anything else. Put this statement in the script first: letter = input ('Enter your answer: ', 's'); Write the script using a single nested if-else statement (elseif clause is permitted). Write the script from the previous exercise using a switch statement instead