gistfile1.js

//First you create your new page element to later be appended to the tab element

     var amlPage = new apf.page({
            id         : "chatUser" + chatUserID,
            caption    : chatUserName,
            name       : "groupchat",
            closebtn   : "true",
            childNodes : [
                new apf.toolbar({
                      height  : "6"
                    , 'class' : "tb_private_chat"
                }),
                new apf.hbox({
                    align   : "top",
                    height  : "100%-47",
                    'class' : "collab_output_container",
                    childNodes : [
                        new apf.text({
                        	id         : "txtChat" + chatUserID,
                            flex       : "1",
                            scrolldown : "true",
                            textselect : "true",
                            height     : "291",
                            'class'    : 'chat_text'
                        }),
                        
                        new apf.scrollbar({
                            'for'   : "txtChat" + chatUserID,
                            margin  : '0 0 2 0',
                            skinset : 'collaborate',
                            skin    : 'sbcollaborators',
                            width   : '9'
                        })
                    ]
                }),
                
                new apf.hbox({
                    height  : "41",
                    width   : "100%",
                    edge    : "8 7 7 7",
                    'class' : "hboxchatinput",
                    childNodes : [
                        new apf.input({
                            height : "24",
                            width  : "100%"
                        })
                    ]
                })
            ]
        });

//and then something like..

     tab_obj.appendChild(amlPage);