How can I trap error in an sqldatasource control

I'm trying to trap for an index error when inserting. I'm using an SQLDataSource. Is there a way to do this?

    Protected Sub UploadPictureDataSource_Inserting(ByVal sender As Object, ByVal e As System.Web.UI.WebControls.SqlDataSourceCommandEventArgs) Handles UploadPictureDataSource.Inserting
        ShowErrorMessage("Only one picture file of type (jpeg, gift, or png) can be uploaded for each client.")
    End Sub

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