Determine if the strings carry the same elements

Compare the given two strings, return true if both have the same letters. Otherwise false.

Sample Code:

function letterMod(str1,str2) {
// Enter your logic here...
}

Examples:

Input: 'silent','Listen'
Output: true
Explanation: Both strings consist of the same letters.

Input: 'cAR','arc'
Output: true
Explanation: Both strings consist of the same letters.