Index: lams_gradebook/src/java/org/lamsfoundation/lams/gradebook/service/GradebookService.java
===================================================================
diff -u -r62aaf160878735888d077bf28fac3c1989bb8fbd -r86c3193e3b58ecd032fc3df4503627e510ec6c0e
--- lams_gradebook/src/java/org/lamsfoundation/lams/gradebook/service/GradebookService.java	(.../GradebookService.java)	(revision 62aaf160878735888d077bf28fac3c1989bb8fbd)
+++ lams_gradebook/src/java/org/lamsfoundation/lams/gradebook/service/GradebookService.java	(.../GradebookService.java)	(revision 86c3193e3b58ecd032fc3df4503627e510ec6c0e)
@@ -98,6 +98,7 @@
 import org.lamsfoundation.lams.util.ExcelCell;
 import org.lamsfoundation.lams.util.FileUtil;
 import org.lamsfoundation.lams.util.MessageService;
+import org.lamsfoundation.lams.util.WebUtil;
 import org.lamsfoundation.lams.web.session.SessionManager;
 import org.lamsfoundation.lams.web.util.AttributeNames;
 import org.springframework.web.context.WebApplicationContext;
@@ -193,9 +194,12 @@
 		if ((activityState == LearnerProgress.ACTIVITY_ATTEMPTED)
 			|| (activityState == LearnerProgress.ACTIVITY_COMPLETED)) {
 		    // Set the activityLearner URL for this gradebook activity
-		    activityDTO.setActivityUrl(Configuration.get(ConfigurationKeys.SERVER_URL)
-			    + activity.getTool().getLearnerProgressUrl() + "&userID=" + learner.getUserId()
-			    + "&toolSessionID=" + toolSession.getToolSessionId().toString());
+		    String activityUrl = Configuration.get(ConfigurationKeys.SERVER_URL)
+			    + activity.getTool().getLearnerProgressUrl();
+		    activityUrl = WebUtil.appendParameterToURL(activityUrl, "userID", learner.getUserId().toString());
+		    activityUrl = WebUtil.appendParameterToURL(activityUrl, "toolSessionID",
+			    toolSession.getToolSessionId().toString());
+		    activityDTO.setActivityUrl(activityUrl);
 		}
 	    }