注意：未定义的变量：content_search -opencart 2

I got these errors when i'm configured the theme template..

Notice: Undefined variable: content_search in C:\xampp\htdocs\www\catalog\view\theme\so-maxshop3\template\common\header.tpl on line 322

<div class="col-sm-4 header_search">
                    <?php  echo $content_search; ?>
                    </div>

Notice: Undefined variable: content_menu in C:\xampp\htdocs\www\catalog\view\theme\so-maxshop3\template\common\header.tpl on line 364

<div class="header-bottom-menu col-md-10 col-sm-9 col-xs-4">
                 <?php if (trim($content_menu)) :
                echo $content_menu;
                endif; ?>
                <!-- //end Navbar -->
            </div>

Notice: Undefined variable: content_block2 in C:\xampp\htdocs\www\catalog\view\theme\so-maxshop3\template\common\home.tpl on line 24 Notice: Undefined variable: content_block3 in C:\xampp\htdocs\www\catalog\view\theme\so-maxshop3\template\common\home.tpl on line 25

  <?php if ($content_top): ?>
        <?php echo $content_top ?> 
    <?php endif; ?>
   <?php echo $content_block2 ?>
   <?php echo $content_block3 ?>

i tried by put isset but no output. Please help me to fix this error.Thank You.