Selecting checkbox in datatable automatically

Hi,
I am desinging a datatable with checkbox in every row. I want to select all the checkboxes initially when the page loads. Please help.
Here is the snippet. http://webix.com/snippet/099fe73f

You can use something like next

  ready:function(){
    this.eachRow(function(id){
      this.getItem(id).ch1 = 1;
    });
  }

http://webix.com/snippet/12d72ac4

Thank you so much for the support maksim.