repeat = function repeat(str, count) {  
        if(typeof(count) == "undefined") {  
        count =1;  
      }  
      return count < 1 ? '' : new Array(count + 1).join(str);  
        }  
    console.log(repeat('Ha!'));  
    console.log(repeat('Ha!',2));  
    console.log(repeat('Ha!',3));