OnClientChange
The OnClientChange occurs when certain Cell value has changed
The event handler receives two parameters:
The instance of the Spreadsheet control firing the event.
An eventArgs parameter containing the following methods:
get_range return a reference to the SpreadsheetRange object, associated with the cell.
get_widget reference to the Spreadsheet Kendo widget.
<telerik:RadSpreadsheet RenderMode="Lightweight" runat="server" id="RadSpreadsheet1" OnClientChange="OnClientChange">
</telerik:RadSpreadsheet>
function OnClientChange(sender, eventArgs) {
eventArgs.get_range().get_value() //returns the new value of the cell
}