//opens an existing file when this button is clicked
        private void OpenWorkshop_Click(object sender, EventArgs e)
        {
            // create and show dialog box that enables user to open file
            OpenFileDialog fileChooser = new OpenFileDialog();
            DialogResult   result      = fileChooser.ShowDialog();
            WorkshopName   name        = new WorkshopName();

            // exits the open event handler if user clicks Cancel
            if (result != DialogResult.Cancel)
            {
                try
                {
                    fileName = fileChooser.FileName;        // get name of file from user

                    if (fileName.Contains(".sup") == false) // show error if the selected file is not a .sup file
                    {
                        MessageBox.Show("The file must be a .sup file", "Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
                    }

                    else
                    {
                        WorkshopForm workshop = new WorkshopForm(fileName, name.WsName); //creates object of the workshopForm
                        workshop.MdiParent = this;                                       //makes this form the parent form of the display workshop form
                        workshop.Show();
                    }
                }
                //exception when a file doesn't exist
                catch (FileNotFoundException)
                {
                    //tells the user if file does not exist
                    MessageBox.Show("This File does not exist", "Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
                }
            }
        }
        //saves everything for the workshop file
        private void SaveWorkshop_Click(object sender, EventArgs e)
        {
            WorkshopForm active = ((WorkshopForm)ActiveMdiChild);

            //determines if an existing file is being saved
            if (active != null)
            {
                active.SaveWkShop();
            }

            else
            {
                MessageBox.Show("You must open a new or existing file before saving", "Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
            }
        }
        private void NewWorkshop_Click(object sender, EventArgs e)
        {
            WorkshopName name = new WorkshopName(); //creates object of the workshopName form

            name.ShowDialog();                      //use showDialog because name is not a child of this Mdi

            if (fileName != "")
            {
                fileName += ".sup";                                              //makes the file a .sup file

                WorkshopForm workshop = new WorkshopForm(fileName, name.WsName); //creates object of the workshopForm
                workshop.MdiParent = this;                                       //makes this form the parent form of the display workshop form
                workshop.Text      = name.WsName;
                workshop.Show();
            }
        }
        private void InsertItem_Click(object sender, EventArgs e)
        {
            WorkshopForm active = ((WorkshopForm)ActiveMdiChild);

            active.AddItem();
        }
        private void Update_Click(object sender, EventArgs e)
        {
            WorkshopForm active = ((WorkshopForm)ActiveMdiChild);

            active.UpdateItem();
        }
        private void DeleteItem_Click(object sender, EventArgs e)
        {
            WorkshopForm active = ((WorkshopForm)ActiveMdiChild);

            active.OmitItem();
        }