function test(str) {  var counts = {};  var reg = new RegExp('[A-Za-z]'); for(var i=0;i<str.length;i++){ var char = str.charAt(i); if(reg.test(char) == true){ if(counts.hasOwnProperty(char)){
                counts[char]++; if(counts[char] == 3) return char;
            }else {
                counts[char] = 1;
            }
        }
    }
}