Use the ClientInstanceName property to specify a unique client-side identifier for the ASPxSpreadsheet control. The ClientInstanceName property's value can be used on the client side to programmatically access the client object rendered for the ASPxSpreadsheet control in client-side script. This property is particularly important in referencing the ASPxSpreadsheet control when it is contained within a naming container (for instance, within an ASPxPopupControl's window).
If the ClientInstanceName property is not specified for a control, the control's client identifier is generated automatically and equals the value of the control's ID property. Note that in this case, client-side programmatic access to the control is not allowed when the control is contained within a naming container.