求助delphi [Error] :')'expected but identifier 'where' found

[forener123]

unit Unit6;

interface

uses
Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
Dialogs, StdCtrls, Buttons, DBTables, DB;

type
Tfrmpasswd = class(TForm)
Label1: TLabel;
Label2: TLabel;
Label3: TLabel;
Label4: TLabel;
Edit1: TEdit;
Edit2: TEdit;
Edit3: TEdit;
Edit4: TEdit;
BitBtn1: TBitBtn;
BitBtn2: TBitBtn;
Table1: TTable;
Query1: TQuery;
procedure FormCreate(Sender: TObject);
procedure BitBtn1Click(Sender: TObject);
private
{ Private declarations }
public
{ Public declarations }
end;

var
frmpasswd: Tfrmpasswd;

implementation

{$R *.dfm}



procedure Tfrmpasswd.FormCreate(Sender: TObject);
var username:string;
begin
edit3.Text :='';
edit4.Text :='';
edit1.Text :='admin';
username :=edit1.Text ;
query1.Close;
query1.SQL.Clear;
query1.SQL.Add('select passwd from admin where userid="'+username+'"');
query1.open;
edit2.Text :=trim(query1.FieldValues['passwd']);
end;

procedure Tfrmpasswd.BitBtn1Click(Sender: TObject);
begin
if edit3.text<>edit4.Text then
begin
showmessage('你的新密码与确认密码不相符，请重新输入新密码！');
exit;
end;
query1.close;
query1.SQL.Clear ;
query1.SQL.Add('update admin set passwd="'+edit3.text+'"+'where userid="'+username+'"');
query1.execsql;
showmessage('用户密码更新成功！');
frmpasswd.close;
end;

end.


这是一个简单的密码修改窗体代码，请高手指点怎么修改能运行啊！！
错误如标题所示！

[dinoalex]

query1.SQL.Add('update admin set passwd="'+edit3.text+'"+' where userid="'+username+'"');

where前加一空格

[shijies]

或者加 ），换一行再用add（）加一句。

[forener123]

多谢二位前辈，错误我已经找到！！