WordPress CMS link problems

Hi,
I tried to make a CMS out of WordPress and actually succeded, but wiyh a few problems.
One of these problems would be that i renamed the index.php of wordpress to ‘show_blog.php’ . Evrything fine, I managed to make all the links like when you click on the post and all to work, but i’m stuck on the search form 😐 in stead of going to query http://www.domain.com/blog/show_blog.php?=search it still goes to http://www.domain.com/blog/?=search and i can’t get to find a solution 😐 can anyone help me?
Here is my searchform.php code:

<form method="get" id="searchform" action="<?php bloginfo('url'); ?>/">
		<input type="text" value="<?php the_search_query(); ?>" placeholder="search" name="s" id="s" />
		<input type="submit" id="searchsubmit" value="Search" />
</form>

and you can see the website at http://www.testeweb.com/blog/ and click on the blog button (*offtopic evrything you see on the site is wordpress, no static html :P)
need help ASAP