Не понимаю код

type
  TForm1 = class(TForm)
    ADOConnection1: TADOConnection;
    DBGrid1: TDBGrid;
    DataSource1: TDataSource;
    Edit1: TEdit;
    Edit2: TEdit;
    Label1: TLabel;
    Label2: TLabel;
    Edit4: TEdit;
    Label4: TLabel;
    Button1: TButton;
    Edit5: TEdit;
    Button2: TButton;
    Label5: TLabel;
    Label6: TLabel;
    Label7: TLabel;
    Label8: TLabel;
    DBEdit2: TDBEdit;
    DBEdit3: TDBEdit;
    DBEdit4: TDBEdit;
    DBEdit1: TDBEdit;
    Edit3: TEdit;
    StatusBar1: TStatusBar;
    DBNavigator1: TDBNavigator;
    ComboBox1: TDBComboBox;
    ADOQuery1: TADOQuery;
    procedure Button1Click(Sender: TObject);
    procedure Button2Click(Sender: TObject);
    procedure DBGrid1KeyPress(Sender: TObject; var Key: Char);
    procedure ComboBox1Change(Sender: TObject);
    procedure FormShow(Sender: TObject);
    procedure FormCreate(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;
 
var
  Form1: TForm1;
  fs: string;
implementation
 
{$R *.dfm}
 
procedure TForm1.Button1Click(Sender: TObject);
var a,b: integer;
var c,k: double;
begin
a := StrToInt(Edit1.Text);
b := StrToInt(Edit2.Text);
c := StrToFloat (DBEdit4.Text);
 
k := 656/b*a*c/100;
 
Edit4.Text := FloatToStr(k);
 
 
 
 
 
 
end;
 
procedure TForm1.Button2Click(Sender: TObject);
var d,k,p: double;
begin
d := StrToInt(Edit5.Text);
k := StrToFloat(Edit4.Text);
 
p := k-d;
Edit3.Text := FloatToStr(p);
end;
 
procedure TForm1.DBGrid1KeyPress(Sender: TObject; var Key: Char);
begin
fs:=fs+key;
DBGrid1.DataSource.DataSet.Locate('Ребенок', fs, [loPartialKey]);
StatusBar1.Panels.Items[0].Text:='Ищем: '+fs;
end;
 
procedure TForm1.ComboBox1Change(Sender: TObject);
var MyTab: String;
begin
MyTab := Trim(ComboBox1.Text);
if (MyTab <>'') then
begin
with ADOQuery1 do
begin
Close;
SQL.Clear;
SQL.Append('SELECT * FROM '+ MyTab +'');
Open;
end;
end;
end;
 
procedure TForm1.FormShow(Sender: TObject);
begin
ADOConnection1.GetTableNames(ComboBox1.Items, True);
end;
 
procedure TForm1.FormCreate(Sender: TObject);
begin
ADOQuery1.SQL.Clear;
ADOQuery1.SQL.Add('SELECT * FROM Березовский');
ADOQuery1.Active:=True;
end;
 
end.