Код:
<script type="text/javascript"> defaultPict = "https://forumupload.ru/uploads/0000/12/13/61-1.png" var arr=document.getElementsByTagName("ul") i=1 while(arr[++i]){ str=arr[i].innerHTML if(str.indexOf("pa-avatar")==-1) { q=str.toLowerCase() if((pos=q.indexOf("<li class=pa-from>"))!=-1 || (pos=q.indexOf("<li class=\"pa-from\">"))!=-1 || (pos=q.indexOf("<li class=pa-reg>"))!=-1 || (pos=q.indexOf("<li class=\"pa-reg\">"))!=-1){ nstr =str.substring(0,pos) nstr+="<li class=\"pa-avatar item2\"><img src="+ defaultPict +" alt=\"Аватар\" /></li>" nstr+=str.substring(pos) arr[i].innerHTML=nstr }}} </script>