on (release) {
if (operator == 'add'){
answer = number(num1)+ number(num2);}
if (operator == 'subtract'){
answer = number(num1)- number(num2);}
if (operator == 'multiply'){
answer = number(num1)* number(num2);}
if (operator == 'divide'){
answer = number(num1)/ number(num2);}