You can check if an element is hidden with the following jQuery code:
// 查看 CSS 设置 display:[none|block], 忽略 visibility:[true|false]
$(element).is(":visible");
Example
<div id="hide" style="display:none;">I am hidden content, you cannot see me.</div>
<div id="show" style="display:block;">I am visible content, you can see me.</div>
Try it »