var
     Form1: TForm1;                   //yeah, the magnetic window... 
     LastX, LastY: Integer;           //keep the coordinates of cursor 
     WinampRect:TRect;              //stores the region of target window 
     hwnd_Winamp:HWND;        //the handle of Winamp's main window     Then fill the OnMouseDown and OnMouseMove events of Form1 as shown below.    procedure TForm1.FormMouseDown(Sender: TObject; Button: TMouseButton;  
      Shift: TShiftState; X, Y: Integer); 
const 
      ClassName='Winamp v1.x';   //the classname of Winamp's main window 
      { Replace the line with "ClassName='TAppBuilder'" if your Delphi itself hungers for some magnetic power. } 
begin     //save the coordinates 
LastX := X;
LastY := Y; 
//try to locate Winamp 
hwnd_Winamp := FindWindow(ClassName,nil); 
if hwnd_Winamp>0 then 
      GetWindowRect(hwnd_Winamp, WinampRect);     end;     procedure TForm1.FormMouseMove(Sender: TObject; Shift: TShiftState; X, Y: Integer); 
var 
     nLeft,nTop:integer; 
begin 
//check whether the form is being dragged 
     if HiWord(GetAsyncKeyState(VK_LBUTTON)) > 0 then 
     begin
           //calculate new position 
           nleft := Left   X - LastX; 
           nTop := Top   Y - LastY;
//adjust the position if Winamp is found 
ifhwnd_Winamp>0 then
        Magnetize(nleft,ntop); 
     SetBounds(nLeft,nTop,width,height); 
   end;    end;    Have a pause here. Before unveiling the codes of "magnetize()", I wanna give an unofficial definition of "window-magnetization". That is, "a process of adjusting the position of source window to align it and target window on one plane surface when they are close to some predefined extent". A little bit confusing huh? Well, sample codes are sometimes better than dull explanation. Let's continue...          procedure TForm1.Magnetize(var nl,nt:integer);
     //two simple embedded functions
     function Min(a,b:integer):integer;
     begin
     ifa>b then result:=b else result:=a;
     end;
     function Max(a,b:integer):integer;
     begin
     if a < b then result:=b else result:=a;
     end;
var
     H_Overlapped,V_Overlapped:boolean;
     tw,ww,wh:integer;
const
     MagneticForce:integer=50;
     { in other words, when two windows are nearer than 50 pixels, they will be aligned automatically.  Remember, 50 is used for demonstration purposes only. 
        It's quite exaggerative if you want to simulate the effect of Winamp. }
begin    ww := WinampRect.Right-WinampRect.Left;
tw := Max(WinampRect.Right,nl Width)-Min(WinampRect.Left,nl);
H_Overlapped := tw<=(Width ww);    wh := WinampRect.Bottom-WinampRect.Top;
tw := Max(WinampRect.Bottom,nt Height)-Min(WinampRect.Top,nt);
V_Overlapped := tw<=(Height wh);    //change the position when the two windows are close enough
if H_Overlapped then
     begin
          if Abs(WinampRect.Bottom-nt)< MagneticForce then nt := WinampRect.Bottom
          else if Abs(nt Height-WinampRect.Top)< MagneticForce then nt := WinampRect.Top-Height;
     end;    if V_Overlapped then
     begin
          if Abs(WinampRect.Right-nl)< MagneticForce then nl := WinampRect.Right
          else if Abs(nl Width-WinampRect.Left)< MagneticForce then nl := WinampRect.Left-Width;
     end;
end;