diff --git a/checkin_notes b/checkin_notes
index 97a0b66e98..bfd1077344 100644
--- a/checkin_notes
+++ b/checkin_notes
@@ -6862,3 +6862,9 @@ Charlie 20 Aug 2008
         WizardAttachProject.cpp
         common/
             wxFlatNotebook.cpp
+
+David  20 Aug 2008
+    - lib: fix typo
+
+    lib/
+        filesys.C
diff --git a/db/bossa_schema.sql b/db/bossa_schema.sql
index c1b9d29a8d..2ceda93689 100644
--- a/db/bossa_schema.sql
+++ b/db/bossa_schema.sql
@@ -35,6 +35,7 @@ create table bossa_job_inst (
     app_id              integer     not null,
     job_id              integer     not null,
     user_id             integer     not null,
+    batch_id            integer     not null,
     finish_time         integer     not null,
     timeout             integer     not null,
     calibration         tinyint     not null,
diff --git a/html/inc/bossa_db.inc b/html/inc/bossa_db.inc
index 61387806a1..d8b690feaa 100644
--- a/html/inc/bossa_db.inc
+++ b/html/inc/bossa_db.inc
@@ -257,10 +257,14 @@ class BossaJobInst {
         }
 
         $now = time();
-        $clause = "(create_time, app_id, job_id, user_id, calibration) values ($now, $app->id, $job->id, $user->id, $job->calibration)";
+        $clause = "(create_time, app_id, job_id, user_id, batch_id, calibration) values ($now, $app->id, $job->id, $user->id, $job->batch_id, $job->calibration)";
         $id = BossaJobInst::insert($clause);
         return BossaJobInst::lookup_id($id);
     }
+    function delete_aux($clause) {
+        $db = BossaDb::get();
+        return $db->delete_aux('bossa_job_inst', $clause);
+    }
 
     // app-callable functions
     //
diff --git a/html/inc/bossa_example4.inc b/html/inc/bossa_example4.inc
index 2cbbfe7ee6..03bc70a0a0 100644
--- a/html/inc/bossa_example4.inc
+++ b/html/inc/bossa_example4.inc
@@ -56,7 +56,7 @@ function job_show($job, $inst, $user) {
         echo "
             <span class=link>
             <a href=\"javascript: void(0)\">
-            <img border=0 align = left src=images/info_icon.png>
+            <img border=0 align = left src=example4_images/info_icon.png>
             <span>
             $f->type $c
             </span>
@@ -64,7 +64,7 @@ function job_show($job, $inst, $user) {
             </span>
         ";
         echo "
-            <a href=bossa_example4.php?bji=$inst->id&action=delete&index=$i><img border=0 align=right src=images/close_button.jpg></a>
+            <a href=bossa_example4.php?bji=$inst->id&action=delete&index=$i><img border=0 align=right src=example4_images/close_button.jpg></a>
             </span>
         ";
         $i++;
diff --git a/html/ops/bossa_admin.php b/html/ops/bossa_admin.php
index 083fa3584e..ffdcb28290 100644
--- a/html/ops/bossa_admin.php
+++ b/html/ops/bossa_admin.php
@@ -201,7 +201,7 @@ function show_batches($app_id) {
     table_header("ID", "Name", "Calibration?", "Created", "Jobs", "Completed");
     foreach ($batches as $batch) {
         table_row(
-            "$batch->id <a href=bossa_admin.php?action=show_batch&batch_id=$batch->id>(show jobs)</a>",
+            "$batch->id | <a href=bossa_admin.php?action=show_batch&batch_id=$batch->id>show jobs</a> | <a href=bossa_admin.php?action=clear_batch_confirm&batch_id=$batch->id>delete instances</a>",
             "$batch->name",
             $batch->calibration?"yes":"no",
             time_str($batch->create_time),
@@ -257,6 +257,28 @@ function show_user() {
     page_tail();
 }
 
+function clear_batch_confirm($batch_id) {
+    page_head("Confirm delete instances");
+    echo "
+        This will permanently delete all results from this batch.
+        <p>
+        Are you sure you want to do this?
+        <p>
+        <a href=bossa_admin.php?action=clear_batch&batch_id=$batch_id>Yes</a>
+    ";
+    page_tail();
+}
+
+function clear_batch($batch_id) {
+    page_head("Deleting instances");
+    if (BossaJobInst::delete_aux("batch_id=$batch_id")) {
+        echo "Job instances deleted.";
+    } else {
+        echo "Database error.";
+    }
+    page_tail();
+}
+
 $user = get_logged_in_user();
 
 $db = BossaDb::get();
@@ -320,15 +342,15 @@ case 'show_user':
     show_user();
     exit;
 case 'show_batches':
-    $app_id = $_GET['app_id'];
+    $app_id = get_int('app_id');
     show_batches($app_id);
     exit;
 case 'show_batch':
-    $batch_id = $_GET['batch_id'];
+    $batch_id = get_int('batch_id');
     show_batch($batch_id);
     exit;
 case 'job_show_insts':
-    $job_id = $_GET['job_id'];
+    $job_id = get_int('job_id');
     job_show_insts($job_id);
     exit;
 case 'hide':
@@ -343,6 +365,14 @@ case 'unhide':
     if (!$app) error_page("no such app");
     $app->update("hidden=0");
     break;
+case 'clear_batch_confirm':
+    $batch_id = get_int('batch_id');
+    clear_batch_confirm($batch_id);
+    exit;
+case 'clear_batch':
+    $batch_id = get_int('batch_id');
+    clear_batch($batch_id);
+    exit;
 case '':
     show_all();
     exit;
diff --git a/lib/filesys.C b/lib/filesys.C
index 8375e8c1c0..2b283e31c3 100644
--- a/lib/filesys.C
+++ b/lib/filesys.C
@@ -494,11 +494,11 @@ int boinc_copy(const char* orig, const char* newf) {
 #elif defined(__EMX__)
     char cmd[1024];
     sprintf(cmd, "copy \"%s\" \"%s\"", orig, newf);
-    return system(cmd_esc);
+    return system(cmd);
 #else
     char cmd[1024], cmd_esc[1024];
     sprintf(cmd, "cp \"%s\" \"%s\"", orig, newf);
-    return system(cmd_esc);
+    return system(cmd);
 #endif
 }