Making a Search Command in the Side Bar(missing security token problem)

[Hell Bomb]

i have made a pretty basic search bar and i was wondering a couple things about it

1. How do i fix the security token issue with in it.
2. How do i make it so it doesn't stretch the side bar.
3. How can i change the submit button to something i choose.

<form action="search.php?do=process" method="post" name="vbform" id="searchform" >
<input type="text" name="query" />
<input type="submit" />
</form> </div>