The example shows the client selection built-in feature of Telerik RadGrid. Single
   row can be selected by clicking the row itself (note that you need to set AllowRowSelect="true"
   to enable client row selection). There is also a GridClientSelectColumn, which you
   can use to select and unselect row(s) client-side. You can use it to select all
   the rows using the check box at the header.
   Furthermore, you can select multiple rows after setting the AllowMultiRowSelection
   property of the grid to true. Several rows can be selected either by:
 
      
          - holding the Ctrl key when clicking the rows 
- dragging a region with the mouse to select all underlying rows. To accomplish this 
              task you have to set the ClientSettings -> Selecting -> EnableDragToSelectRows 
              property to true.
- clicking a row, holding the Shift key and clicking another row upwards/downwards
    
     Later on, you can unselect a row by holding the 
Crtl key and clicking the
     row. You don't need this if you have GridClientSelectColumn added.
     Additionally, the GridItem provides 
SelectableMode property which could be set to:
        
            - None.
- ServerSide.
- ServerAndClientSide (the default value).
    The selected items will be available through the 
SelectedRows client collection
    of the respective RadGridTable.
    
    
    Finally, there is also a checkbox column (called 
GridClientSelectColumn which
    displays a checkbox control for each item in the column. This allows you to select
    grid rows client-side automatically when you change the status of the checkbox to
    checked. Additionally, if you choose 
AllowMultiRowSelection = true for the
    grid, a checkbox will be displayed in the column header to toggle the checked/selected
    state of the rows simultaneously (according to the state of that checkbox in the
    header). To allow selection through the client select column only, set the 
ClientSettings
    -> Selecting -> UseClientSelectColumnOnly property to 
true
    (default value is false).