Search Functions NOT WORKING and returns 404 Error

HI

My Website search functions are not working at all.
Its not working for my pages and not for posts as well.

Disabled plugins – Not worked

here is code I am using: searchform.php

<h2>Search</h2>
<form id=”searchform” method=”get” action=”<?php bloginfo(‘home’); ?>/search.php”> <input type=”text” value=”Search….” onfocus=”if (this.value == ‘Search….’) {this.value = ”;}” onblur=”if (this.value == ”) {this.value = ‘Search….’;}” size=”18″ maxlength=”50″ name=”s” id=”s”/> <input type=”submit” id=”searchsubmit” value=”GO” /></form>

Can anyone help?