C#

if(e.KeyCode == Keys.Enter){
   e.Handled = true;//stops the beep/bonk noise
   e.SupressKeyPress = true;//it bypasses the KeyPress event
   
   txtYouNameIt.Focus();//focuses on the control you specify
}

private void Comunal_KeyDownHandler(object sender, System.Windows.Forms.KeyEventArgs e)
{
   if (e.KeyCode == Keys.Enter)
   {
       e.Handled = true;
       // true means go forwards
       this.GetNextControl((Control)sender, true).Focus();
   }
}

public List<string> CleanupText(List<string> inputLines)
    {
    List<string> outputLines = new List<string>();
    foreach (string s in inputLines)
        {
        // Note: the Trim() and Replace() ensure that (a) there are no false hits and (b) no false misses, respectively
        if (s.Trim().Replace('\t', ' ').Contains(" "))
            outputLines.Add(s);
        else
            outputLines.Add(string.Concat(s, " 0"));
        }
    return outputLines;
    }

public void DoFormStuff(ClassA ca)
    {
    using (MyForm frm = new MyForm())
        {
        frm.ClassA = ca;
        frm.ShowDialog(this);
        }
    }