private void EditOffset(int selected)
        {
            // Will need to pass in the currently selected item
            frmOffset dialog = new frmOffset(frmOffset.Mode.Edit);

            dialog.SetAmp(offsets[selected].Amplitude);
            dialog.SetPhase(offsets[selected].Phase);
            DialogResult r = dialog.ShowDialog();

            if (r == DialogResult.OK)
            {
                var newPhase = dialog.GetPhase();
                var newAmp   = dialog.GetAmp();
                offsets[selected].Phase     = newPhase;
                offsets[selected].Amplitude = newAmp;


                lsvOffsets.Items[selected] = CreateListViewItem(offsets[selected]); //grabs selected items from offsets list, stores in listviewitem, adds to listview
            }
        }
        private void AddOffset()
        {
            frmOffset    dialog = new frmOffset(frmOffset.Mode.Add);
            DialogResult r      = dialog.ShowDialog();

            if (r == DialogResult.OK)
            {
                // Add the offset to the listview (lsvOffsets)

                // Create new variable to hold phase and amplitude values
                PhaseAmplitudeOffset newOffset = new PhaseAmplitudeOffset
                {
                    Phase     = dialog.GetPhase(),
                    Amplitude = dialog.GetAmp()
                };

                offsets.Add(newOffset); //List<PhaseAmplitudeOffset> offset

                // create new listview item to store phase/amp values and add to list

                lsvOffsets.Items.Add(CreateListViewItem(newOffset));
            }
        }