Views: Searching for a particular node id

Hi

I am trying to create a view that takes a parameter from a form and displays the full body of the node as a page. The parameter is the node ID and therefore the output will have only one node. The view consists of:

Basic Information
  - Name - BriefIdSearch
Page
  - URL - searchid/$arg/id
  - View Types - Full Nodes
Arguments
  - NodeID - Summary Unsorted (I really want Full Node, but there is no option)
Filters
  - Node:Published Equals Yes
  - Taxonomy:Terms for Briefs - is one of - [Urgent, Essential, Other]

The code for the form is

<form action="searchid/$arg.php" method="post">
  Search by id...
  <input type="text" name="BriefIdSearch" /><input type="submit" value="Search" />
</form>

If I enter a known node id in the search form I get a 'Page Not Found' and the address is www.example.com/searchid/$arg.php (what I want to see is, if the node id is 627 www.example.com/node/627 or even www.example.com/searchid/627). I am relatively new to views, php and drupal and believe that the problem is in passing the node id from the form to the view. I have searched the forums but cannot find anything similar - a step by step guide would be great

Thanks in advance.
TJ