private void button3_Click(object sender, EventArgs e) { businesslayer bl = new businesslayer(); if (CName.Text.Equals("") || Phone.Text.Equals("") || SSN.Text.Equals("") || Email.Text.Equals("") || ImagePath.Text.Equals("")) { MessageBox.Show("Please,Fill the inputs"); } else { Regex regex = new Regex(@"^([\w\.\-]+)@([\w\-]+)((\.(\w){2,3})+)$"); Match match = regex.Match(Email.Text); if (match.Success) { bl.InsertCust(CName.Text, Phone.Text, SSN.Text, Email.Text, ImagePath.Text); } else { MessageBox.Show(Email.Text + " is incorrect"); } } }