// Command to delete the material
public void deleteMaterial(int materialId)
{
// Delete the material from the database
MaterialModel.deleteMaterial(materialId);
// Remove the material from the deleted material list
MaterialModel deletedMaterial = materialList.Where(mat => mat.materialId == materialId).First();
// Remove from the active material list
materialList.Remove(deletedMaterial);
originalMaterialList.Remove(deletedMaterial);
// Add to the deleted material list
deletedMaterialList.Add(deletedMaterial);
}