Ext.create('Ext.tab.Panel', {
    width: 900,
    layout:'fit',
    activeTab: 0,
    items: [
        Ext.create('Ext.form.Panel',{
            title:'test',
            style:{border:'1px solid red;',width:'700px !important',margin:'0px auto'},
            items:[
                {
                    xtype: 'hiddenfield', //1
                    name: 'hiddenfield1',
                    value: 'Hidden field value',
                    allowBlank:false
                },
                {
                    xtype: 'displayfield', //2
                    name: 'displayfield1',
                    fieldLabel: 'Display field',
                    value: 'Display field <span style="color:red;">value</span>'
                }
            ]
        
        })
                
                     ],
    renderTo : Ext.getBody()
});