function binarySearch(array, x, startIndex, endIndex) {
    if (endIndex < startIndex)
        return -1;

    var mid = (endIndex + startIndex) / 2;

    if(array[mid] < x){
        if(array[endIndex - 1] >= x)
            return binarySearch(array,x,mid+1,endIndex);
        else
            return binarySearch(array,x,startIndex,mid-1);
    }
    if(array[startIndex] <= val)
        return binarySearch(array,x,startIndex, mid-1);
    else
        return binarySearch(array,x,mid+1,endIndex);
}