如何用DateTimePicker这个控件来作为TQuery.Filter的一个参数（在程序中控制的）。(100分)

请看以下代码:
with frmQueryGeneral.Query1 do
begin
if Memo1.Text <> '' then
begin
if CheckBox1.Checked = true then
begin
Filter := Memo1.Text + ' AND (录单日期 >= '''+DateToStr(DateTimePicker1.Date)+''') AND (录单日期 <''' +DateToStr(DateTimePicker2.Date)+''')';
Filtered := True;
end
else
begin
Filter := Memo1.Text;
Filtered := True;
end;
end
else
begin
if CheckBox1.Checked = true then
begin
Filter := ' (录单日期 >= '''+DateToStr(DateTimePicker1.Date)+''') AND (录单日期 <''' +DateToStr(DateTimePicker2.Date)+''')';
Filtered := true;
end
else
begin
Filter := '';
Filtered := true;
end

end;
frmQueryGeneral.Memo1.Text :=Filter;
end;

Query.Filtered := True;
Query.Filter := '字段>=''Int(DateTimePicker1.AsDateTime)'' '
注意:用int()函數才能包含等于部份的時間.

多人接受答案了。