Search box error

After a long searching, I’ve found this code to make a search box by category, that I’m going to put at the side bar as a text:

<form method=”get” id=”searchform” action=”<?php bloginfo(‘home’); ?>” />
<div>
<input type=”text” name=”s” id=”s” value=”” />
<input type=”hidden” name=”cat” value=”3″ />
<input type=”submit” id=”searchsubmit” value=”Search” />
</div>
</form>

But after the first search, an error appeared at the screen and then I saw that the http://www.mysite.com:80/<s=searchingword&cat=3 but this :80 not suppose to be there.

How I’ll fix it?? I’m putting the code at the right place?