Button under datatable

Hello,
I have some problems to understand the design structure of web. I try to use a datatable inside a modal window and under this datatable I want a close button for the modal window. I try to use a container but it will not work, the datatable is empty and the controls are rendered without any position. Sample:

 webix.ui({
  view:"window", 
  modal:true,
  id:"editwin",
  position:"center",
  head:"DataTable", left:50, top:50,
  height:400, width:500,
  body:{
    cols:[
      {
        view:"datatable", id: "datawin",
        columns:[
          { id:"id_case", header:"id", width:50},
          { id:"body_case",
           template:"#!body_case#",
           header:"Text",
           width:400,
           fillspace:true}
        ],
        fixedRowHeight:false, 
        rowLineHeight:25,
        rowHeight:25,
        url: "itemsource.php?id=213",
        on:{
          onAfterLoad:function(){
            webix.delay(function(){
              this.adjustRowHeight("body_case", true);
              this.render();
            }, this);
          },
          onColumnResize:function(){
            this.adjustRowHeight("body_case", true);
            this.render();
          }
        }
      },
      {view:"button", value:"close", click:function(){
        this.getTopParentView().close();
      }}
    ]
  }
});   

Hello!
Here is a solution to your question: https://webix.com/snippet/fad7e59b