Diman:
Thanks for reporting this bug.
We have fixed it.
We will publish new version for that .
And you can fix it now, by modify the IM_ChatForm.aspx:
line 7:
<title><%=ChatApi.GetUser(int.Parse(Request.QueryString["UserId"])).DisplayName%></title>
line 94:
var _target_username=<%=ChatWebUtility.EncodeJScriptString(ChatApi.GetUser(int.Parse(Request.QueryString["UserId"])).DisplayName)%>;
Regards , Terry .