public bool NavigateBackEnabled { get; }

Public ReadOnly Property NavigateBackEnabled As Boolean
	Get

// Navigate to the previous report in the history if available
private void button7_Click(object sender, System.EventArgs e)
{
    if (this.reportViewer1.NavigateBackEnabled)
    {
        this.reportViewer1.NavigateBack();
    }
}

' Navigate to the previous report in the history if available
Private Sub button7_Click(sender As Object, e As System.EventArgs)
    If Me.ReportViewer1.NavigateBackEnabled Then
        Me.ReportViewer1.NavigateBack()
    End If
End Sub