DOS compilation fixes

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@12915 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/generic/helpext.cpp

@@ -98,7 +98,9 @@ wxExtHelpController::DisplayHelp(const wxString &relativeURL)
    }
    else
       return true;
+
 #elif  defined(__WXPM__)
+
    wxString url;
    url << m_MapFile << '\\' << relativeURL.BeforeFirst('#');
 //   will have to fix for OS/2, later.....DW
@@ -111,8 +113,16 @@ wxExtHelpController::DisplayHelp(const wxString &relativeURL)
 //   }
 //   else
       return TRUE;
-#else
-   // assume UNIX
+
+#elif defined(__DOS__)
+
+   wxString command;
+   command = m_BrowserName;
+   command << wxT(" file://")
+           << m_MapFile << WXEXTHELP_SEPARATOR << relativeURL;
+   return wxExecute(command) != 0;
+
+#else // UNIX
    wxString command;
 
    if(m_BrowserIsNetscape) // try re-loading first