[javascript] How to return values in javascript

Its very simple. Call one function inside another function with parameters.

    function fun1()
    {
     var a=10;
     var b=20;
     fun2(a,b); //calling function fun2() and passing 2 parameters
    }

   function fun2(num1,num2)
   {
    var sum;
    sum = num1+num2;
    return sum;
   }

   fun1(); //trigger function fun1