private void go_Click(object sender, EventArgs e)
 {
     if (parent_a.Text == "-" || go.Text == "Continue")
     {
         inside             = new Inside(Convert.ToInt32(memNum.Text));
         refresh.Enabled    = true;
         reset.Enabled      = true;
         go.Text            = "pause";
         derivative.Enabled = false;
     }
     else
     {
         refresh.Enabled    = false;
         go.Enabled         = true;
         go.Text            = "Continue";
         derivative.Enabled = true;
     }
 }