--- SIPB/trunk/server/common/oursrc/athrun/athrun.sh	2012-11-01 18:12:49.048292474 -0400
+++ SIPB/trunk_oursrc/server/common/oursrc/athrun/athrun.sh	2012-11-28 18:31:33.856046457 -0500
@@ -17,6 +17,13 @@
 *)
   locker=$1
   program=$2
+  if [ ! -d "/mit/$locker" ]; then
+      echo "Locker $locker not found. Did you try 'add $locker'?"
+      exit 2
+  elif [ ! -x "/mit/$locker/arch/@sys/bin/$program" ]; then
+      echo "Program $program not found on locker $locker."
+      exit 3
+  fi
   shift 2;
   exec "/mit/$locker/arch/@sys/bin/$program" "$@"
   ;;