I must apologize for the problems you had with my code. I guess I didn't take my testing far enough with it.

Sounds like I was making this more complicated than it needed to be anyway.
I think this is probably what you're looking for:
PHP Code:
<center>
<p>Search My Website</p>
<form action='/path/to/search.php' method='get'>
<input type='hidden' name='template_demo' value='/path/to/templates/template.php'/>
<input type='hidden' name='site' value='0'/>
<input type='hidden' name='path' value=''/>
<input type='hidden' name='result_page' value='/path/to/search.php'/>
<input type='text' class='phpdiginputtext' size='15' maxlength='50' name='query_string' value=''/>
<input type='submit' class='phpdiginputsubmit' name='search' value='Go...'/>
<input type='hidden' name='limite' class='phpdigselect' value='10'>
</form>
This time I've thoroughly tested my code, so I know it works.