MemAlloc equivalent in Delphi 3

I am trying to port the following Delphi 1 code over to Delphi 3, however, the D3 compiler reports "Undeclared identifier: MemAlloc"

Evidently MemAlloc is no longer used with Win32?   What must I do to make the following D1 code compatible with D3/Win32?

Thanks.

-------------

var
Info: PBitmapInfo;
InfoSize: Integer;
Image: Pointer;
ImageSize: Longint;
begin
 with Bitmap do
  begin
    GetDIBSizes(Handle, InfoSize, ImageSize);
    Info := MemAlloc(InfoSize);