AutoComplete functionality for Text box in WinForms

AutoCompleteStringCollection AutoComp = null;

txtFName.AutoCompleteMode = AutoCompleteMode.Suggest;
txtFName.AutoCompleteSource = AutoCompleteSource.CustomSource;

AutoComp.Add("AAAA");  
AutoComp.Add("BBBB");  
AutoComp.Add("GGGG");  

txtFName.AutoCompleteCustomSource = AutoComp; 

Many ways to get your application path

// The following returns the application executable path with exe name
Console.WriteLine(System.Environment.CommandLine); 
//  or
Console.WriteLine(System.Windows.Forms.Application.ExecutablePath);
//  or
Console.WriteLine(System.Reflection.Assembly.GetExecutingAssembly().Location);
        
// The following returns just the application executable path
Console.WriteLine(System.Environment.CurrentDirectory); 
//  or
Console.WriteLine(System.IO.Directory.GetCurrentDirectory());
//  or
Console.WriteLine(System.Windows.Forms.Application.StartupPath);
//  or
Console.WriteLine(System.AppDomain.CurrentDomain.BaseDirectory);
//  or
Console.WriteLine(System.Reflection.Assembly.GetExecutingAssembly().CodeBase); 

Send Email programmatically using your Gmail account

protected void btnSendEmail_Click(object sender, EventArgs e)
{
   // Create Mail Message Object with content that you want to send with mail.
   System.Net.Mail.MailMessage MyMailMessage = new System.Net.Mail.MailMessage("dotnetguts@gmail.com","myfriend@yahoo.com",
"This is the mail subject", "Just wanted to say Hello");

   MyMailMessage.IsBodyHtml = false;

   // Proper Authentication Details need to be passed when sending email from gmail
   System.Net.NetworkCredential mailAuthentication = new
   System.Net.NetworkCredential("dotnetguts@gmail.com", "myPassword");

   // Smtp Mail server of Gmail is "smpt.gmail.com" and it uses port no. 587
   // For different server like yahoo this details changes and you can
   // Get it from respective server.
   System.Net.Mail.SmtpClient mailClient = new System.Net.Mail.SmtpClient("smtp.gmail.com",587);

   // Enable SSL
   mailClient.EnableSsl = true;

   mailClient.UseDefaultCredentials = false;

   mailClient.Credentials = mailAuthentication;

   mailClient.Send(MyMailMessage);
}