delphi调用vb的dll出错，请高手指教

VB写的的dbpapi.dll里有个声明的原型是：
Public Declare Function DBPCreate Lib "dbpapi.dll" (ByVal sips As Long, ByVal susers As Long, ByVal spasss As Long, ByRef wport As Integer, ByVal nsize As Long) As Long
只知道原型，没有相应的DLL源代码。

我在Delphi里写的代码如下：
var
  Form1: TForm1;

  Function DBPCreate(sips:pchar; susers: pchar; spasss: pchar; var wport:Integer; nsize : integer) : Integer; stdcall external 'dbpapi.dll';
 
implementation

{$R *.dfm}

procedure TForm1.Button1Click(Sender: TObject);
var
 ipaddress:pchar;
 username:pchar;
 password:pchar;
 ipport:Integer;
 dwn: Integer;
begin

  ipaddress:= '127.0.0.1';
  username:= 'admin';
  password:= 'admin';
  ipport:= 12084;
  dwn := DBPCreate(ipaddress,username,password,ipport,1); \\断点执行到这里时候报内存错误
 end;
end.
不知道我调用的哪里有问题？请高手指教！

自己顶起来

Public Declare Function DBPCreate Lib "dbpapi.dll" (ByVal sips As Long, ByVal susers As Long, ByVal spasss As Long, ByRef wport As Integer, ByVal nsize As Long) As Long

Function DBPCreate(sips:integer; susers:integer; spasss: integer; var wport:word; nsize : integer) : Integer; stdcall external 'dbpapi.dll';


vb Long->delphi integer;
vb Integer->delphi Word;