Kpalíndromo em javascript usando recursividade

gistfile1.js

function kpalindrome (word, k){
  var len = word.length,
      lastCharIndex = len - 1;
 
    if (len === 0 || len === 1) {
      return true;
    }
 
    if (word[0] === word[lastCharIndex]) {
      // Remove first and last characteres of the string
      word = word.substr(0, lastCharIndex).substr(1);
      return kpalindrome(word, junk);
    } else if (k > 0) {
      var splitLastChar = word.substr(0, lastCharIndex),
          splitFirstChar = word.substr(1);
          
      return ( kpalindrome( splitLastChar, --k ) || kpalindrome( splitFirstChar, --k ) ); 
    }
    
    return false;
}