How can i make this functional

Question

JavaScript with switch case
https://code.sololearn.com/WZTObAba3hw2/?ref=app

Answer 1

var val= prompt("enter Yes/No"); //taking user input by prompt

switch(val)
{
case 'Yes':
console.log("ok then")
break;
case 'No':
console.log("fine")
break;
default :
console.log("no")
}

Answer 2

The condition for the cases must be of a type that val can be compared to, e.g. a string or a number.

But currently Yes and No are not defined