diff --git a/idev b/idev
index e0cb25f..074b765 100755
--- a/idev
+++ b/idev
@@ -1,7 +1,7 @@
 #!/bin/bash
-#set -x
-# User is forces to use either SGE or SLURM options, except
-# -p and -q can both be used for either batch system
+# set -x
+# User is forced to use either SGE or SLURM options, except
+# -p and -q can both be used for either batch system.
 #
 # For Stampede the system startup file /etc/profile.d/z95_idev.<csh|sh>
 # takes care of sourcing /tmp/idev_<csh|sh>_env.<jobid> if the file
@@ -55,16 +55,18 @@
 #Hidden grace-serial queue 
 #   Added -p <queue_name> option to squeue (to see queue)
 #   Allow -n 1 for default for grace-serial queue
-#   Changed format from 9 to 15 chars for queue name (grace-serial is 12 chars)
-#   Abort if -N is used in grace-serial queue.
-#                                                01/21/2016 KentM 
-#
+#   Changed format from 9 to 15 for queue name (grace-serial is 12 chars)
+#   grace-serial queue users are allowed only 1 interactive job
+#                                                01/29/2016 KentM 
+# TODO
+# Update version number.
 #------------------------------------------------------------------------------
 #
 #               Versions Number
    IDEV_VER=1.00
    IDEV_SETUP_VER=1.00
 
+#NOTE:  use hostname -f
 #Determine the system
   myhostname=`hostname -f`
   if [[ $myhostname =~ nid ]] ; then
@@ -73,13 +75,14 @@
      MY_SYS=`echo $myhostname | awk 'BEGIN { FS = "." } ; { print $2 }'`
   fi
 
-
+#800 comment her 800_Wfix
   srun=off        # Don't use srun on Stampede
 # trap ctrl-c and call ctrl_c()
 trap ctrl_c INT EXIT
 did_exit=no
 exit_msg=""
 
+#800  comment for 900_Wfix
 #                         Trap Function.  Deletes job on exit of this script
 function ctrl_c() {
                          #Job submitted, and job id available.
@@ -696,7 +699,7 @@ fi
    fi
 
    if [[ $known_option == "no" ]]; then
-                     echo -e "\n ERROR: **The $1 option is not know."
+                     echo -e "\n ERROR: **The $1 option is not known."
                      echo -e "          To see options, execute: idev -help."
                      do_exit=yes; OPT_ERR=2
             
@@ -749,6 +752,35 @@ if [[ $total_tasks_set == no && $nodes_set == yes ]] ; then
 
 fi
 
+#      if grace-serial queue     
+if [[ $MY_QUEUE =~ grace-serial ]]; then
+
+  squeue -p $MY_QUEUE "$squeue_opts" -u $USER | \
+            awk '$3 ~ /idv[0-9][0-9][0-9][0-9][0-9]/' | \
+            awk '{print $5}' | grep R >/dev/null
+  if [ $? = 0 ]; then
+    using_node=`squeue -p $MY_QUEUE "$squeue_opts" -u $USER | \
+            awk '$3 ~ /idv[0-9][0-9][0-9][0-9][0-9]/' | \
+            awk '{print $8}' `
+    echo ""
+    echo " ERROR:  Only one ONE idev interactive session allowed in $MY_QUEUE queue."
+    echo ""
+    echo " You are executing idev again in the $MY_QUEUE queue."
+    echo "    In this queue only 1 idev interactive job is allowed."
+    echo "    You may have multiple windows open to the job (node) for an active"
+    echo "    IDEV session by opening a new window on a login node, and SSHing"
+    echo "    to the node of the job with the command:"
+    echo ""
+    echo "                 ssh -Y $using_node   "
+    echo ""
+    echo " In a new window you can customize your environment if"
+    echo " you want to work interactively on different projects."  
+    echo ""
+    do_exit=yes; OPT_ERR=2
+  fi
+fi
+
+
 ############################################end  Dependent options
 
 
@@ -1395,6 +1427,7 @@ $MY_RESERVATION
 
 $idev_pwd_cmd
 $idev_rm_perl5
+#                         Remove old files (needed for grace-serial queue).
 rm -rf /tmp/idev_${USER}_${idev_login_shell}_env.[0-9]*
 $DIR/idev_utils env_replication ${idev_login_shell} \$SLURM_JOB_ID
 $CREATE_NODE_LIST_CMD
@@ -1495,7 +1528,7 @@ fi
 #####
           while [ $found_env_file == 1 ]; do
           
-              ssh -o "StrictHostKeyChecking no" $node "ls /tmp/idev_${idev_login_shell}_env.${JOBID}" >& /dev/null
+              ssh -o "StrictHostKeyChecking no" $node "ls /tmp/idev_${USER}_${idev_login_shell}_env.${JOBID}" >& /dev/null
               if [[ $? == 0 ]]; then
                  found_env_file=0
                  if [[ $time_waited_env_file > 0 ]]; then
@@ -1534,7 +1567,8 @@ fi
 fi
 
 fi 
+#http://github.com/milfeld2/idivx
 #trapping
 #http://rimuhosting.com/knowledgebase/linux/misc/trapping-ctrl-c-in-bash
 #http://www.linuxjournal.com/content/use-bash-trap-statement-cleanup-temporary-files
-
+#http://github.com/milfeld/idivx
diff --git a/idev_utils b/idev_utils
index f723dd3..d557e66 100755
--- a/idev_utils
+++ b/idev_utils
@@ -157,7 +157,8 @@ sub env_replication(@){
 
 ##                     Changed for 9.2  my_<shell>... --> idev_<shell>...
 ## $myenv_filename = "/tmp/idev_${my_shell}_env.${my_idev}";
-   $myenv_filename = "/tmp/idev_${USER}_${my_shell}_env.${my_idev}";
+## $myenv_filename = "/tmp/idev_${USER}_${my_shell}_env.${my_idev}";
+   $myenv_filename = "/tmp/idev_$ENV{USER}_${my_shell}_env.${my_idev}";
    if ( $my_shell eq "bash" ){
      $CMD   = "export ";
      $UNCMD = "unset ";