title: Check whether a string contain '&' character only
body: <p>How to check whether a string contains "&amp;" only. I mean that if user will enter &amp; or &amp;&amp;&amp; or a string of '&amp;'. Please note that <a href="http://myurl.com/&amp;var=79" rel="nofollow">http://myurl.com/&amp;var=79</a> or something like this should be ignored. It should check for those string which contains &amp; character. Please help me!!!</p>