求教在指定位置弹出系统菜单的具体用法！分可加。。。

[project]

求教在指定位置弹出系统菜单的具体用法！
我做了一个无标题Form用图片代替标题栏，想实现在点击某个图标是弹出系统菜单。
如：关闭、还原、最大化。。。

[luoweicaisd]

var
mousepos: Tpoint;
begin
if message.lparam = WM_LBUTTONDBLCLK then
showmessage('不要乱动!')
else
if (message.lparam = WM_RBUTTONDBLCLK) then
begin
getcursorpos(mousepos);
popupmenu1.Popup(mousepos.x, mousepos.y);
end;
end;

[luoweicaisd]

var
mousepos: Tpoint;
begin
if message.lparam = WM_LBUTTONDBLCLK then
showmessage('不要乱动!')
else
if (message.lparam = WM_RBUTTONDBLCLK) then
begin
getcursorpos(mousepos);
popupmenu1.Popup(mousepos.x, mousepos.y);
end;
end;

[luoweicaisd]

var
mousepos: Tpoint;
begin
if message.lparam = WM_LBUTTONDBLCLK then
showmessage('不要乱动!')
else
if (message.lparam = WM_RBUTTONDBLCLK) then
begin
getcursorpos(mousepos);
popupmenu1.Popup(mousepos.x, mousepos.y);
end;
end;