getSelections Returns: array
Return an array with the ids of the selected record.
Examples
  
  <button id="btnShowSelection">Show Selections</button>
 <br/><br/>
 <table id="grid"></table>
 <script>
     var grid = $("#grid").grid({
         dataSource: "../Grid/GetPlayers",
         columns: [ { field: "ID" }, { field: "Name" }, { field: "PlaceOfBirth" } ],
         selectionMethod: "checkbox",
         selectionType: "multiple"
     });
     $("#btnShowSelection").on("click", function () {
         var selections = grid.getSelections();
         $.each(selections, function() {
             alert(this);
         });
     });
 </script>