Javascript binary search test

binarysearch.js

function binarySearch(target, data)
{
    if(data.length <= 0) return -1;
    if(data.length == 1 && data[0] != target) return -1;
    
    var midpoint = Math.floor(data.length/2);
    if(data[midpoint] == target)
    {
        return true;            
    } else {
        if(target < data[midpoint]) {
            return binarySearch(target, data.slice(0, midpoint));
        } else {
            return binarySearch(target, data.slice(midpoint, data.length));
        }
    }
}

var data = [0, 2, 4, 8, 16, 32, 64, 128, 256, 512, 1024];
console.log(binarySearch(128, data));