Javascript response please

Have the function CaesarCipher(str,num) take the str parameter and perform a Caesar Cipher shift on it using the num parameter as the shifting number. A Caesar Cipher works by shifting each letter in the string N places in the alphabet (in this case N will be num). Punctuation, spaces, and capitalization should remain intact. For example if the string is "Caesar Cipher" and num is 2 the output should be "Ecguct Ekrjgt".

Examples

Input: "Hello" & num = 4 Output: Lipps

Input: "abc" & num = 0 Output: abc

Function to be solved:

function CaesarCipher(str,num) {

// code goes here

return str;

}

// keep this function call here

console.log(CaesarCipher(readline()));