Check for Palindromes by using cycle

Tell us what’s happening:
hello, guys! this code all doing well excluding non-palindrome word ‘almostomla’. Could you help me to understand what is wrong?

Your code so far

function palindrome(str) {
  str = str.toLowerCase();
  
  var letterFinder = /[\a-z\d]/gi;
  var onlyLetter =str.match(letterFinder);
  var onlyLetter2 = str.match(letterFinder);
  var reverserL = onlyLetter.reverse();
 
  var result; 
  var a;
  var b;
  
   for (var i = 0; i < onlyLetter.length; i++) {
      a = onlyLetter[i];
     for (var j = 0; j < onlyLetter2.length; j++) {
       b = onlyLetter2[j];       
       } result = a[i] === b[i];
        
     } result = a==b;
 
   return result;

}



palindrome("My age is 0, 0 si ega ym.");

Your browser information:

Your Browser User Agent is: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/61.0.3163.100 Safari/537.36.

Link to the challenge:

Since the input and the reversed input has the same length you only need one loop
try this

function palindrome(str) {
  var string = str.toLowerCase();
  var stringReversed = string.match(/[\a-z\d]/gi).reverse();
  var stringnorml = string.match(/[\a-z\d]/gi);
   for (var i = 0; i < stringnorml.length; i++) {
     if(stringnorml[i] != stringReversed[i])
       return false;
   }
   return true;
}

thank you very much, your help was very useful!!!

thank you, Randell. You show me the problem.