关于TIdFTP控件连接FTP服务器超时的问题(50分)

我用TIdFTP控件编写的连接FTP服务器的程序，为什么当超时时就直接停止程序了，请帮我看看这个过程有什么问题，谢谢
procedure connect_ftp;
begin
try
if not Form1.IdFTP1.Connected then
Form1.IdFTP1.Connect(True,-1);
if Form1.IdFTP1.Connected then
begin
Form1.IdFTP1.Disconnect;
Form1.IdFTP1.Abort;
Form1.IdFTP1.Quit;
end;
except
on e:exception do
begin
showMessage(e.Message);
Form1.IdFTP1.Free;
end;
end;
end;

我刚学，实在是搞不懂，程序一超时就提示出错，并且停止了！

delphi自带demo/indy/FTPdemo下的代码：
ConnectButton.Enabled := false;
if IdFTP1.Connected then try
if TransferrignData then IdFTP1.Abort;
IdFTP1.Quit;
finally
//Panel3.Caption := 'Current directory is: ';
CurrentDirEdit.Text := '/';
DirectoryListBox.Items.Clear;
SetFunctionButtons(false);
ConnectButton.Caption := 'Connect';
ConnectButton.Enabled := true;
ConnectButton.Default := true;
end
else with IdFTP1 do try
User := UserIDEdit.Text;
Password := PasswordEdit.Text;
Host := FtpServerEdit.Text;
Connect;
Self.ChageDir(CurrentDirEdit.Text);
SetFunctionButtons(true);
SaveFTPHostInfo(FtpServerEdit.Text, 'FTPHOST');
finally
ConnectButton.Enabled := true;
if Connected then begin
ConnectButton.Caption := 'Disconnect';
ConnectButton.Default := false;
end;
end;