how to install script live chat code on post

Hi. I have script :

<script id=”sid0020000069589055192″>(function() {function async_load(){s.id=”cid0020000069589055192″;s.src=(window.location.href.indexOf(‘file:///’) > -1 ? ‘http:’ : ”) + ‘//st.chatango.com/js/gz/emb.js’;s.style.cssText=”width:300px;height:500px;”;s.async=true;s.text='{“handle”:”fplsuflercom”,”arch”:”js”,”styles”:{“a”:”0084ef”,”b”:100,”c”:”FFFFFF”,”d”:”FFFFFF”,”k”:”0084ef”,”l”:”0084ef”,”m”:”0084ef”,”n”:”FFFFFF”,”p”:”12.87″,”q”:”0084ef”,”r”:100,”t”:0,”usricon”:0}}’;var ss = document.getElementsByTagName(‘script’);for (var i=0, l=ss.length; i < l; i++){if (ss[i].id==’sid0020000069589055192′){ss[i].id +=’_’;ss[i].parentNode.insertBefore(s, ss[i]);break;}}}var s=document.createElement(‘script’);if (s.async==undefined){if (window.addEventListener) {addEventListener(‘load’,async_load,false);}else if (window.attachEvent) {attachEvent(‘onload’,async_load);}}else {async_load();}})();</script>

Need to stick it on one of my site…
How to do it ???
Anyone plz?