regular control with a dialog frame

[EvilProject]

Hi , I'm writing a script editor and i want to add an autocomplete feature to it just like in VS. now, in VS the Autocomplete list has a frame just like a dialog frame , i want the same frame for my autocomplete list. so i wrote this in my listbox derived class:

        protected override CreateParams CreateParams
        {
            get
            {
                const int WS_DLGFRAME = 0x400000;
                const int WS_BORDER     = 0x800000;
                const int WS_THICKFRAME = 0x40000;                
 
                //const int WS_CAPTION = 0xC00000;
                CreateParams cp = base.CreateParams;
 
                cp.Style = (cp.Style | WS_DLGFRAME | WS_BORDER | WS_THICKFRAME );
                return cp;
            }
        }

but i have two problem with this
1. the frame doesn't look exacly like the VS Frame(the top part of the frame is wider than the othr parts)
2.It seems that enabling the WS_DLGFRAME Style makes the control movable and resizeable to the user ,meaning the user can change the control's Size and position at runtime.

Please help , Amir.