Updated the way the $id reference is selected so that ID's with brackets co...

...ntinue to work and display.

Quick summary:

I am building a shop and using DropKick. I have selects for the shop software that have brackets in their name, like this:

```
<select name="product_option[size]">
<option>Small</option>
<option>Medium</option>
<option>Large</option>
</select>
```

The jQuery selector you were using for fading in the newly created DropKick div was failing, so I rewrote it. This appears to be working fine though!