iBS takes in an array and a value to search for. If the value is found in the array then iBS will return the index where the found value is. If the value is not found in the array then iBS returns false. Uses max min and mid

iBs.js

var iBs = function(arr, num){
	var max = arr.length-1, min = 0; midpt = Math.floor(arr.length/2);
	for(var i=0; i<arr.length-1; i++){
		if(arr[midpt]> num){
			max = midpt;
			midpt --; 
		}
		else if(arr[midpt]<num){
			min = midpt;
			midpt ++; 
		}
	}
	if(arr[midpt] === num){
		return midpt;
	}else if(midpt === min || midpt === max){
		return false ;
	}
};

// var arr = [-90,-19,0,2,12,29,33,190,320];
// iBs(arr, 5)              => false
// iBs(arr, 12)             => 4
// iBs(arr, 0)              => 2
// iBs(arr, 190)            => 7