image path in general-template.php

I originally tried that but it’s not working as the input code lies within a function:

function get_search_form($echo = true) {
do_action( ‘get_search_form’ );

$search_form_template = locate_template(array(‘searchform.php’));
if ( ” != $search_form_template ) {
require($search_form_template);
return;
}

$form = ‘<form role=”search” method=”get” id=”form1″ action=”‘ . home_url( ‘/’ ) . ‘” >
<div>
<input type=”text” value=”‘ . get_search_query() . ‘” name=”s” id=”s” />
<input type=”image” id=”searchsubmit” value=”‘. esc_attr__(‘Search’) .'” src=” <?php bloginfo(‘template_directory’); ?>/images/blank.gif” border=”0″/>
</div>
</form>’;

if ( $echo )
echo apply_filters(‘get_search_form’, $form);
else
return apply_filters(‘get_search_form’, $form);
}