Can I write this:

```
<script>var _XXX = false;</script>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

```

or it will cause a problem to the page?

I mean that the script will be before the doctype