add some help for uploading

atlas/templates/atlas/user_uploads.html

@@ -2,7 +2,13 @@
 
 {% block content %}
     <h2>Uploaded dicoms</h2>
-    Click to select cases to import. If no cases are selected all will be seleced/imported.
+    {% if not case %}
+        <div class="alert alert-info" role="alert">
+            Series imported from here will be orphaned (not associated with a case). It is usually better to create a case first and then import directly into the case.
+        </div>
+    {% endif %}
+
+    Click to select cases to import. If no series are selected all will be seleced/imported.<br/>
 
 
     {% if series_list %}