Error accessing method in 3rd party dll

Question

already asked for help a few weeks ago but no one answered and i still wasn't able to figure out what the problem...
i have a 3rd party dll and im trying to access some methods (USING JNI)- i have no problem accessing methods with no parameters and they work fine but a method with parameters just wwont work.
i guess that its something with my syntax - probably incorrect data type when converting from java type to native type...
i dont have any previous expirience with c so help would be appriciated...
heres my java code:
package pavel2.javay;
class Test {
    native String VersionGet();
    native String loadDll();
    native String LogInMT4(int account,String  pass,String server,String a,String v,String c,String d);
    static {
        System.loadLibrary("pavel2");
    public static void main(String args[]) {
        Test t = new Test();
        System.out.println(t.loadDll());
        System.out.println(t.LogInMT4(230622,"qd1bvvs","Orion-DEMO","","","",""));
}and the dll wrapper:
#include <windows.h>
#include <C:\\Program Files\\Java\\jdk1.6.0_10\\include\\jni.h>
#include <C:\\Program Files\\Java\\jdk1.6.0_10\\include\\win32\\jni_md.h>
typedef char*   (*LogIn_MT4)( const int login, const char *password, const char *server, const char *proxyserver,
               const char *proxytype, const char *proxylogin, const char *proxypassword);
HINSTANCE hOle2Dll;
JNIEXPORT jstring JNICALL Java_pavel2_javay_Test_loadDll(JNIEnv * env, jobject jobj){
     hOle2Dll = LoadLibrary(TEXT("D:\\pavel2\\tzmt4api.dll"));
     return  (*env)->NewStringUTF(env, "tzmt4api.dll loaded!!");
     /*if (OleInitialize(NULL) == S_OK)
          if ( hOle2Dll >= 32 )
               //FreeLibrary ( hOle2Dll ) ;
JNIEXPORT jstring JNICALL Java_pavel2_javay_Test_LogInMT4(JNIEnv * env, jobject jobj,jint login, jstring password, jstring server,jstring proxyserver,jstring proxytype,jstring proxylogin,jstring proxypassword){
               LogIn_MT4 fnc ;
               fnc = (LogIn_MT4)GetProcAddress ( hOle2Dll , "LogIn_MT4" ) ;
               if ( fnc == NULL )
                    MessageBox(NULL, TEXT("Error loading Method"), TEXT("Error"), MB_OK);
               else
               const char *pass = (*env)->GetStringUTFChars(env, password, NULL);
               const char *ser = (*env)->GetStringUTFChars(env, server, NULL);
               const char *proxyserv = (*env)->GetStringUTFChars(env, proxyserver, NULL);
               const char *proxyt = (*env)->GetStringUTFChars(env, proxytype, NULL);
               const char *proxylog = (*env)->GetStringUTFChars(env, proxylogin, NULL);
               const char *proxypass = (*env)->GetStringUTFChars(env, proxypassword, NULL);
               int a=fnc(login, pass, ser, proxyserv,proxyt,proxylog,proxypass);
               (*env)->ReleaseStringUTFChars(env, password, pass);
               (*env)->ReleaseStringUTFChars(env, server, ser);
               (*env)->ReleaseStringUTFChars(env, proxyserver, proxyserv);
               (*env)->ReleaseStringUTFChars(env, proxytype, proxyt);
               (*env)->ReleaseStringUTFChars(env, proxylogin, proxylog);
               (*env)->ReleaseStringUTFChars(env, proxypassword, proxypass);
               //return  (*env)->NewStringUTF(env, empty);
               return  (*env)->NewStringUTF(env, "logged");
                         //int c = fnc(login, *password, *server, "", "", "", "");
BOOL APIENTRY DllMain( HMODULE hModule,
                       DWORD  ul_reason_for_call,
                       LPVOID lpReserved
     switch (ul_reason_for_call)
     case DLL_PROCESS_ATTACH:
     case DLL_THREAD_ATTACH:
     case DLL_THREAD_DETACH:
     case DLL_PROCESS_DETACH:
          //todo: unregister class here
          break;
     return TRUE;
}this is the output:
tzmt4api.dll loaded!!
# An unexpected error has been detected by Java Runtime Environment:
# EXCEPTION_ACCESS_VIOLATION (0xc0000005) at pc=0xcccccccc, pid=3792, tid=3824
# Java VM: Java HotSpot(TM) Client VM (11.0-b15 mixed mode, sharing windows-x86)
# Problematic frame:
# C 0xcccccccc
# An error report file with more information is saved as:
# C:\Program Files\TradeZone\TZMT4APInew\Work\hs_err_pid3792.log
# If you would like to submit a bug report, please visit:
# http://java.sun.com/webapps/bugreport/crash.jsp
# The crash happened outside the Java Virtual Machine in native code.
# See problematic frame for where to report the bug.
Process finished with exit code 1
p.s - it looks like the login method works but when returning to java the VM crashes
can anyone help me?

Answer 1

jschell - tried this already and got the same ..
ejp - i cant do this bucause i dont have a .lib and this proccess can run only on windows unfortunately...
my problem is that i dont know the how to create the correct type for the method:
this is the signature:
typedef int  (*LogIn_MT4)( const int login, const char *password, const char *server, const char *proxyserver,
               const char *proxytype, const char *proxylogin, const char *proxypassword);how do i create in c this var types?
int a=fnc(1531, "asas", "asd", "","","","");how do i create
const char *xxx type? and its okay for the int just to write a number or i also need to declare it?