同意帕克，你code似乎什么它需要的方式过于复杂。 这里是我会怎么做快速的样品。

Agree with Parker, you code seems way overcomplicated for what it needs to be. Here is quick sample of how I would do it.

我相信它可以优化和抛光安静了一点，但应该足以让你在正确的道路上。

I am sure it can be optimized and polished quiet a bit, but that should be enough to get you on the right path.