How to click the element in span class? Selenium WebDriver

<span class="infor-social-showDetails message-action-menu">
<span class="message-action-menu-text infor-social-showDetailsText" data-inforprops="{"eventName":"GetDetails","UploadIdentifier":"","MsgId":"76","FeedSource":"4","MsgDate":"1433484223883","IONObjectType":"ION_ALERT"}">                     Show Details                 </span>
</span>

I tried the following xpath but it seems not to be working:

.//*[@id='76']/div/div[3]/span[1]/span

Please do help me.

I appreciate for all of those who will comments about this Thanks!