function logo_display()
{
    ?>
        <input type="file" name="logo" />
        <?php echo get_option('logo'); ?>
   <?php
}
function handle_logo_upload()
{
    if(!empty($_FILES["demo-file"]["tmp_name"]))
    {
        $urls = wp_handle_upload($_FILES["logo"], array('test_form' => FALSE));
        $temp = $urls["url"];
       return $temp;
    }
    return $option;
}
function display_theme_panel_fields()
{
    add_settings_section("section", "All Settings", null, "theme-options");
    add_settings_field("logo", "Logo", "logo_display", "theme-options", "section");
    register_setting("section", "logo", "handle_logo_upload");
}
add_action("admin_init", "display_theme_panel_fields");