Compiling with -std=c++11 requires blanks between string literals
and macros defining strings.

--- dialogmain.cpp	2016-03-02 20:31:01.000000000 +0100
+++ dialogmain.cpp	2016-12-27 22:03:26.774405881 +0100
@@ -28,7 +28,7 @@
 #define VERSION "1.0"
 
 static const char* about_message=
-PROGRAM_NAME" v"VERSION"\n\
+PROGRAM_NAME " v" VERSION "\n\
 Copyright (C) 2015, 2016 Andriy Martynets <martynets@volia.ua>\n\
 License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>.\n\
 This program comes with ABSOLUTELY NO WARRANTY.\n\
@@ -37,7 +37,7 @@
 More information on <https://github.com/martynets/dialogbox/>.\n";
 
 static const char* about_html_message=
-"<h3>"PROGRAM_NAME" version "VERSION"</h3>\
+"<h3>" PROGRAM_NAME " version " VERSION "</h3>\
 <p><b>Copyright (C) 2015, 2016 Andriy Martynets </b><a href=\"mailto:martynets@volia.ua\">martynets@volia.ua</a></p>\
 <p><b>License GPLv3+:</b> GNU GPL version 3 or later <a href=\"http://gnu.org/licenses/gpl.html\">http://gnu.org/licenses/gpl.html</a>.</p>\
 <p>This program comes with ABSOLUTELY NO WARRANTY. \
@@ -45,7 +45,7 @@
 under certain conditions. See the GNU GPL for details.</p>\
 <p>More information on <a href=\"https://github.com/martynets/dialogbox/\">https://github.com/martynets/dialogbox/</a>.</p>";
 
-static const char* default_title=PROGRAM_NAME" v"VERSION;
+static const char* default_title=PROGRAM_NAME " v" VERSION;
 
 static void help();
 static void version();
@@ -104,7 +104,7 @@
 static void help()
 {
 	const char* usage=
-"Usage:	"PROGRAM_NAME" [options]\n\
+"Usage:	" PROGRAM_NAME " [options]\n\
 Translate commands on stdin into widgets of GUI dialogbox and output user\n\
 actions to stdout.\n\
 \n\