`.selectedContainer` with non-collapsed selections

Without knowing the signature of `makeTextSelection`, it's unclear what these parameters mean. Could you make explicit variables, named in such a way to describe what they do, and pass them into the function? For example

```javascript
var startElement = p,
      endElement = p,
      startPos = 0,
      endPos = 3;
makeTextSelection(wymeditor, startElement, endElement, startPos, endPos);
```

The above names are examples, I don't know if they apply or are accurate or not.