Cancel/Close the Grid Popup Editor Window

I had a requirement that if a condition was met, when a user clicked Add New Record, it would close the popup window, and display a message instead, accomplished with js like this:

function editmode(e) {
        if (e.model.isNew()) {
            var target = $("#cathTestDate").data("kendoDropDownList");
            var len = target.dataSource.data().length;
            e.preventDefault();
            this.editRow($(e.currentTarget).closest("tr"));
            alert(len);
        }
    }

 Declare in the grid:

@(Html.Kendo().Grid<Model.Models.CathReport>()
            .Name("cathreportgrid")
            .Events(e => {
                e.Edit("editmode");
            })