Problema com o permalink e a busca

no searchform.php ta assim:

<?php

$s = '';
global $_GET;
if( isSet($_GET) and isSet($_GET['s']) ){
	$s = esc_html( trim( stripcslashes( $_GET['s'] ) ) );
}

?>
<div class="widget_search">
<form action="<?php echo home_url(); ?>" class="searchform" method="get">
  <input type="text" name="s" class="searchfield"
		 value="<?php echo $s;?>" />
  <div class="button_wrapper"><input type="submit" value="" name="Submit" class="searchbutton" /></div>
  <div class="clear"></div>
</form>

</div>