帮忙看下写法对不,需要隐藏按钮,如图写了,但是没有生效实现效果
```html
<button id="print" class="toolbarButton print hiddenMediumView" title="Print" tabindex="33" data-l10n-id="print" style="display:none" >
<span data-l10n-id="print_label">Print</span>
</button>
<button id="download" class="toolbarButton download hiddenMediumView" title="Download" tabindex="34" data-l10n-id="download" style="display:none" >
<span data-l10n-id="download_label">Download</span>
</button>
document.getElementById('kmi-pdf-panel').src = 'module/moduleCustomer/program/B02M/B0212A/viewerM.html?file=' + dialog.currentFile.esop_content
+'&openfile=false&viewbookmark=false&printfile=false&download=false#zoom=page-width';
var pdfElem = document.getElementById('kmi-pdf-panel');
document.getElementById('print').style.display = 'none';
document.getElementById('download').style.display = 'none';
```