Resetting a program in delphi - delphi

Question

I am doing this program in Delphi 7 and using a Page-Control do any of you have a quick way of resetting the Check Boxes and Combo Boxes that is op the page ? With out calling each Check Box and changing its Properties ? Because their is about 150 Check Boxes in the program and don't want to type every ones name out to reset it to unchecked ?
I Tried to use the following code :
var
i : Integer;
cb : TCheckBox;
cbx : TComboBox;
begin
ADOQuery1.SQL.Clear;
for i := 1 to (ComponentCount) do
Begin
if Components[i] is TCheckBox then
begin
cb := TCheckBox(Components[i]);
cb.checked := false;
end;
if Components[i] is TComboBox then
begin
cbx := TComboBox(Components[i]);
cbx.ItemIndex := -1;
end;
end;
End;
But I get a error List out od Bounds ? Any ideas why ?

Answer 1

Off the top of my head....This should run.
procedure ResetControls(aPage:TTabSheet);
var
loop : integer;
begin
if assigned(aPage) then
begin
for loop := 0 to aPage.controlcount-1 do
begin
if aPage.Controls[loop].ClassType = TCheckBox then
TCheckBox(aPage.Controls[loop]).Checked := false
else if aPage.Controls[loop].ClassType = TComboBox then
TComboBox(aPage.Controlss[loop]).itemindex := -1;
end;
end;
end;
edit: Corrected as pointed out by Remy

Answer 2

You could do something like this within the form:
for i := 0 to ComponentCount-1 do
if Components[i] is TCheckBox then begin
cb := TCheckBox(Components[i]);
cb.checked := false;
end;
end;

Answer 3

procedure ResetControls(Container: TWinControl);
var
I: Integer;
Control: TControl;
begin
for I := 0 to Container.ControlCount - 1 do
begin
Control := Container.Controls[I];
if Control is TCheckBox then
TCheckBox(Control).Checked := False
else
if Control is TComboBox then
TComboBox(Control).ItemIndex := -1;
//else if ........ other control classes
ResetControls(Control as TWinControl); //recursive to process child controls
end;
end;