Check the given number is Fibonacci and find the next number in Fibonacci sequence.

Next Fibonacci Sequence Generation

 
var n = 4, fib;
var a = (5 * Math.pow(n, 2) + 4) 
var b=(5 * Math.pow(n, 2) - 4 )


var result = Math.sqrt(a) % 1==0;
var res = Math.sqrt(b) % 1==0;

   
    


//fixed this line
if(result  || res == true)  // checks the given input is fibonacci series
{

fib=Math.round(n* 1.618); // finds the next fibonacci series of given input
console.log("The next Fibonacci number is " + fib);

}
else
{
console.log("The given number is not a fibonacci number");
}