delphi 个人信息输入

小弟刚学Delphi,在制作信息录入模块时，遇到一个问题，错误代码为List Out Of bounds(6),不知道怎么修改，分数虽少，望高手指教一下。

var
Form5: TForm5;
change:boolean;

implementation
USES UNIT4;
{$R *.dfm}

procedure TForm5.Button1Click(Sender: TObject);
begin
with DataMD.CXQuery1 do
begin
close;
sql.Clear;
sql.add ('select * from customer where 账号 =:账号');
parameters.paramByname('账号').value :=Edit4.text;
active:=true;
Open;
DBGRID1.DataSource:=DATAMD.DataSource1 ;
end;
end;

procedure TForm5.Button2Click(Sender: TObject);
begin
with datamd.CXQuery1 do
begin
close;
sql.Clear;
sql.add ('select * from customer where 姓名 =:姓名');
parameters.paramByname('姓名').value :=Edit7.text;
active:=true;
Open;
DBGRID1.DataSource:=DATAMD.DataSource1 ;
end;