function add_months(dt, n)   
 {  
  
   return new Date(dt.setMonth(dt.getMonth() + n));        
 }  
  
dt = new Date();  
console.log(add_months(dt, 10).toString());    
  
dt = new Date(2014,10,2);  
console.log(add_months(dt, 10).toString());  