How to select many rows from gridview using checkbox, then print reports based on selection

[AkAlan]

I have a gridview with a linkbutton for every record which allows my users to print an instruction report based on the selected rows ID field. My users are saying they would like to be able to select several of the rows and then click one button that would print all selected rows. I'm trying to come up with a solution but am drawing a blank. Any suggestions?
Here is how I am setting the reports parameter, as you can see there is only one parameter which is the WorkOrderID of the selected row.
I have a class for printing the report as a pdf document rather than a report viewer if that makes any difference. Thanks for any help.

Partial Public Class RwpInstructions
    Inherits Telerik.Reporting.Report
    Public Sub New()
        InitializeComponent()

        Dim cs As New ConnString
        Me.SqlDataSource1.ConnectionString = cs.AAIOMSConnString()
    End Sub
    Public Property setWorkOrderID() As Integer
        Get
            Return CInt(Me.SqlDataSource1.Parameters.Item("@WorkOrderID").Value)
        End Get
        Set(ByVal workOrderID As Integer)

            Me.SqlDataSource1.Parameters("@WorkOrderID").Value = workOrderID
        End Set
    End Property
End Class