d.getFullYear(),'-',pad2(d.getMonth()+1/*sigh*/),
        '-',pad2(d.getDate()),
        ' ',pad2(d.getHours()),':',pad2(d.getMinutes()),
        ':',pad2(d.getSeconds())
      ].join('');
    };
    cf.prototype = {



      scrollIntoView: function(){
        this.e.content.scrollIntoView();
      },
      setMessage: function(m){
        const ds = this.e.body.dataset;
        ds.timestamp = m.mtime;
        ds.lmtime = m.lmtime;
        ds.msgid = m.msgid;
        ds.xfrom = m.xfrom || '';
        if(m.xfrom === Chat.me){
          D.addClass(this.e.body, 'mine');
        }
        if(m.uclr){
          this.e.content.style.backgroundColor = m.uclr;
          this.e.tab.style.backgroundColor = m.uclr;
        }
        const d = new Date(m.mtime);
        D.clearElement(this.e.tab);
        var contentTarget = this.e.content;
        var eXFrom /* element holding xfrom name */;
        if(m.xfrom){
          eXFrom = D.append(D.addClass(D.span(), 'xfrom'), m.xfrom);
          D.append(
            this.e.tab, eXFrom,
            D.text(" #",(m.msgid||'???'),' @ ',theTime(d))
          );
        }else{/*notification*/
          D.addClass(this.e.body, 'notification');
          if(m.isError){
            D.addClass([contentTarget, this.e.tab], 'error');
          }
          D.append(

            // Used by Chat.reportErrorAsMessage()
            D.append(contentTarget, m.xmsg);
          }else{
            contentTarget.innerHTML = m.xmsg;
          }
        }
        this.e.tab.addEventListener('click', this._handleLegendClicked, false);
        if(eXFrom){
          eXFrom.addEventListener('click', ()=>this.e.tab.click(), false);
        }
        return this;
      },
      /* Event handler for clicking .message-user elements to show their
         timestamps. */
      _handleLegendClicked: function f(ev){
        if(!f.popup){
          /* Timestamp popup widget */