Index: trunk/ippTools/src/magictool.c
===================================================================
--- trunk/ippTools/src/magictool.c	(revision 21004)
+++ trunk/ippTools/src/magictool.c	(revision 21005)
@@ -293,5 +293,5 @@
     PXOPT_LOOKUP_STR(workdir, config->args, "-workdir", true, false);
     PXOPT_LOOKUP_S64(exp_id, config->args, "-exp_id", true, false);
-    PXOPT_LOOKUP_S64(diff_id, config->args, "-diff_id", true, false);
+    PXOPT_LOOKUP_S64(diff_id, config->args, "-diff_id", false, false);
 
     // optional
@@ -304,5 +304,5 @@
             0,          // ID
             exp_id,
-            diff_id,
+            diff_id ? diff_id : PS_MAX_S64,
             "reg",      // state
             workdir,
Index: trunk/ippTools/src/magictoolConfig.c
===================================================================
--- trunk/ippTools/src/magictoolConfig.c	(revision 21004)
+++ trunk/ippTools/src/magictoolConfig.c	(revision 21005)
@@ -63,4 +63,6 @@
     psMetadataAddStr(definerunArgs, PS_LIST_TAIL, "-workdir", 0, "define workdir (required)", NULL);
     psMetadataAddS64(definerunArgs, PS_LIST_TAIL, "-exp_id", 0, "define exp_id (required)", 0);
+    // following argument is for compatability
+    psMetadataAddS64(definerunArgs, PS_LIST_TAIL, "-diff_id", 0, "define diff_id", 0);
     psMetadataAddStr(definerunArgs, PS_LIST_TAIL, "-label", 0, "define label", NULL);
     psMetadataAddStr(definerunArgs, PS_LIST_TAIL, "-dvodb", 0, "define dvodb", NULL);