private void button1_Click(object sender, EventArgs e)
        {
            //Validation

            Regex characterVal       = new Regex("^[a-zA-Z]*$");
            Regex characterNumberVal = new Regex("^[a-zA-Z0-9 ]*$");


            //////////////////////////Serial//////////////////////////
            if (txtPhoneSerialNumber.Text.Equals(""))
            {
                MessageBox.Show("Field Must Not Be Blank", "Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
                txtPhoneSerialNumber.Focus();
                return;
            }
            else if (!txtPhoneSerialNumber.Text.All(Char.IsDigit))
            {
                MessageBox.Show("Numbers only!", "Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
                txtPhoneSerialNumber.Focus();
                txtPhoneSerialNumber.Text = "";
                return;
            }
            else if (txtPhoneSerialNumber.Text.Length > 20)
            {
                MessageBox.Show("Serial Number too long!", "Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
                txtPhoneSerialNumber.Focus();
                txtPhoneSerialNumber.Text = "";
                return;
            }



            //////////////////////////Password//////////////////////////
            else if (txtPassword.Text.Equals(""))
            {
                MessageBox.Show("Phone password required, if there is none, then Specify NULL", "Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
                txtPassword.Focus();
                return;
            }
            else if (!characterNumberVal.IsMatch(txtPassword.Text))
            {
                MessageBox.Show("Name must not contain symbols, Letters and Numbers only!", "Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
                txtPassword.Focus();
                txtPassword.Text = "";
                return;
            }
            else if (txtPassword.Text.Length > 20)
            {
                MessageBox.Show("Name Too Long!", "Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
                txtPassword.Focus();
                txtPassword.Text = "";
                return;
            }



            //////////////////////////PhoneType(CBO)//////////////////////////
            else if (String.IsNullOrEmpty(cbophonetype.Text))
            {
                MessageBox.Show("Please Select Phone type", "Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
                return;
            }



            //////////////////////////Description(CBO)//////////////////////////
            else if (String.IsNullOrEmpty(cbbDescription.Text))
            {
                MessageBox.Show("Please Select Cause of Repair", "Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
                return;
            }



            //////////////////////////Description(TXT)//////////////////////////
            else if (!characterNumberVal.IsMatch(txtDescription.Text))
            {
                MessageBox.Show("Please enter a description", "Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
                txtDescription.Focus();
                txtDescription.Text = "";
                return;
            }
            else if (txtDescription.Text.Length > 75)
            {
                MessageBox.Show("Description Too Long!", "Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
                txtDescription.Focus();
                txtDescription.Text = "";
                return;
            }



            ///////////////////////////Cost///////////////////////////
            else if (txtCost.Text.Equals(""))
            {
                MessageBox.Show("Field Must Not Be Blank", "Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
                txtCost.Focus();
                return;
            }
            else if (!txtCost.Text.All(Char.IsDigit))
            {
                MessageBox.Show("Positive, Whole numbers only!", "Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
                txtCost.Focus();
                txtCost.Text = "";
                return;
            }
            else if (txtCost.Text.Length > 5)
            {
                MessageBox.Show("Price too long!", "Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
                txtCost.Focus();
                txtCost.Text = "";
                return;
            }



            //Changes description if its empty
            else if (txtDescription.Text.Equals(""))
            {
                txtDescription.Text.Equals("No Details");
                return;
            }

            //Adds repair to system
            Repair repair = new Repair(Int32.Parse(txtRepairID.Text), txtPhoneSerialNumber.Text, txtPassword.Text, "In Progress", cbophonetype.Text + "  -  " + cbbDescription.Text + "  -  " + txtDescription.Text, Int32.Parse(txtCustomerID.Text), Int32.Parse(txtCost.Text));

            repair.addRepair();

            //Display success message
            MessageBox.Show("Repair Added", "Success");

            //reset UI
            txtPhoneSerialNumber.Text = "";
            txtPassword.Text          = "";
            txtCustomerID.Text        = "";
            lblCustomerName.Text      = "Select a Customer...";
            txtDescription.Text       = "";
            txtRepairID.Text          = Repair.nextRepairID().ToString("0000");
            cbophonetype.Text         = "";
            cbbDescription.Text       = "";

            grpRepairDetails.Visible = false;
            btnSubmit.Visible        = false;
        }