         <FormGroup>
             <InputGroup className = 'webapp-examples-search'>
                 <FormControl
-                    ref         = 'search'
-                    type        = 'text'
-                    placeholder = 'Search'
+                    ref         = {'search'}
+                    type        = {'text'}
+                    placeholder = {'Search'}
                     value       = {@props.search_str ? ''}
                     onKeyUp     = {@handle_search_keyup}
                     onChange    = {@search}

            <Col sm={12}>
                Selected language <code>{@props.lang}</code> has no data.
                You can help by contributing more content at{' '}
                <a href={REPO_URL} target="_blank">
                    {'sagemathinc/cocalc-assistant'}
                </a>.
            </Col>

                    onClick      = {click}
                >
                    {lvl1} → {lvl2} → <span style={fontWeight: 'bold'} dangerouslySetInnerHTML={__html : title_hl}></span>
                    {' '}
                    {<span className={'snippet'} dangerouslySetInnerHTML={__html : snippet}></span> if snippet?.length > 0}
                </li>
        }
        </ul>
