function repeat_string(string, count)   
  {  
    if ((string == null) || (count < 0) || (count === Infinity) || (count == null))  
      {  
        return('Error in string or count.');  
      }  
        count = count | 0; // Floor count.  
    return new Array(count + 1).join(string);  
  }  
  
console.log(repeat_string('a', 4.6));  
console.log(repeat_string('a'));  
console.log(repeat_string('a', -2));  
console.log(repeat_string('a', Infinity));