I got such incomplete information after calling this web service 2 to 3 times. Initially 2 times i got blank reply. Now When I used HTTPQueryInfo it showed following message H T T P / 1 . 1 4 0 0 B a d R e q u e s t S e r v e r : M i c r o s o f t - I I S / 5 . 0 D a t e : F r i , 2 8 S e p 2 0 0 7 0 8 : 3 5 : 5 1 G M T X - P o w e r e d - B y : A S P . N E T X - A s p N e t - V e r s i o n : 2 . 0 . 5 0 7 2 7 C a c h e - C o n t r o l : p r i v a t e C o n t e n t - L e n g t h : 0 My web service contains just one method “HelloWorld” which does not take any input parameters and returns the “HelloWorld” string to the calling application. My code of calling web service is following. LPTSTR AcceptTypes[2] = {TEXT("text/xml"), NULL}; DWORD dwFlags = INTERNET_FLAG_NO_CACHE_WRITE |INTERNET_FLAG_KEEP_CONNECTION; HINTERNET hNet = InternetOpen(L"EvcWebService", INTERNET_OPEN_TYPE_PRECONFIG, NULL, NULL, 0 ); if (hNet) { HINTERNET hSession = InternetConnect(hNet, _T("10.37.54.93"), INTERNET_DEFAULT_HTTP_PORT, _T(""), _T(""), INTERNET_SERVICE_HTTP, 0, 0); if (hSession) { HINTERNET hRequest = HttpOpenRequest(hSession, _T("POST"), _T("/TestService/Service.asmx?wsdl"), TEXT("HTTP/1.1"),NULL, (LPCTSTR*)AcceptTypes, dwFlags, 0); if (hRequest) { TCHAR szSoapAction[256]; _tcscpy( szSoapAction, _T("Content-Type: text/xml;charset=utf-8\n") ); _tcscat( szSoapAction, _T("SOAPAction: \"") ); _tcscat( szSoapAction, _T("http://tempuri.org/HelloWorld") ); _tcscat( szSoapAction , _T("\"\0\r\n\r\n") ); TCHAR szSoap[512]; _tcscpy(pszSoap, _T("") ); _tcscat(pszSoap, _T("") ); _tcscat(pszSoap, _T("") ); _tcscat(pszSoap, _T("") ); _tcscat(pszSoap, _T("") ); _tcscat(pszSoap, _T("") ); // _tcscat(pszSoap, _T("") ); _tcscat(pszSoap, _T("") ); _tcscat(pszSoap, _T("") ); BOOL bSent = HttpSendRequest(hRequest, szSoapAction, _tcslen(szSoapAction), szSoap, _tcslen(szSoap) ); if(bSent) { called HTTPQueryInfo..... } This HTTPQueryInfo returns bad request. But this code works fine on Win32 and give Bad Request on WinCE. Please let me know how should i b

wrote: I want to know what is the reason behind this?? why such difference in Debug and Release build ?? Stack corruption causes the crash. The correct signature of a message handler, the function takes a WPARAM and an LPARAM (which are pushed onto the stack when the function is called) and returns an LRESULT (which is popped from the stack when the function returns). In the incorrect version of your code, the fun() function is being called as if it had this signature, even though the fun() function does not, and as a result there is stack corruption. The fact that it works in debug mode is a coincidence, possibly due to padding added by the compiler in debug compilations. Incidentally, are you still using VC 6.0? The error in signatures for message handlers is flagged as a compiler error in newer versions of Visual Studio. Mike