var
_younum:integer;
begin
_yournum := StrToIntDef(Edit1.Text,0);
with adoquery1 do
begin
close;
SQL.text := 'select kcsl,kcsl-'+IntToStr(_yournum)+' as diffnum from kctable where kcsl<' +IntToStr(_yournum)+'';
Open;
.....
var
_younum:integer;
begin
_yournum := StrToIntDef(Edit1.Text,0);
with adoquery1 do
begin
close;
SQL.text := 'select kcsl,kcsl-'+IntToStr(_yournum)+' as diffnum from kctable where kcsl<' +IntToStr(_yournum);
Open;
.....