[javascript] Validation to check if password and confirm password are same is not working

function validate()
{
  var a=documents.forms["yourformname"]["yourpasswordfieldname"].value;
  var b=documents.forms["yourformname"]["yourconfirmpasswordfieldname"].value;
  if(!(a==b))
  {
    alert("both passwords are not matching");
    return false;
  }
  return true;
}