Index: lams_contentrepository/src/java/org/lamsfoundation/lams/contentrepository/SimpleVersionDetail.java
===================================================================
diff -u -r08950e1090443c3423a3d1c587416a2fccd8bbdf -rb3ab9dedd256ee8c388d395b33b12486730b2f2c
--- lams_contentrepository/src/java/org/lamsfoundation/lams/contentrepository/SimpleVersionDetail.java	(.../SimpleVersionDetail.java)	(revision 08950e1090443c3423a3d1c587416a2fccd8bbdf)
+++ lams_contentrepository/src/java/org/lamsfoundation/lams/contentrepository/SimpleVersionDetail.java	(.../SimpleVersionDetail.java)	(revision b3ab9dedd256ee8c388d395b33b12486730b2f2c)
@@ -38,7 +38,7 @@
  * 
  * @author Fiona Malikoff
  */
-public class SimpleVersionDetail implements IVersionDetail {
+public class SimpleVersionDetail implements IVersionDetail, Comparable {
 
 	private Long versionId;
 	private Date createdDateTime;
@@ -138,4 +138,5 @@
     	}
     }
     
+    
 }
Index: lams_tool_lamc/src/java/org/lamsfoundation/lams/tool/mc/pojos/McOptsContent.java
===================================================================
diff -u -r9db7a5bb39fecf9a0f1ae5cf2a9f701d2aa1532f -rb3ab9dedd256ee8c388d395b33b12486730b2f2c
--- lams_tool_lamc/src/java/org/lamsfoundation/lams/tool/mc/pojos/McOptsContent.java	(.../McOptsContent.java)	(revision 9db7a5bb39fecf9a0f1ae5cf2a9f701d2aa1532f)
+++ lams_tool_lamc/src/java/org/lamsfoundation/lams/tool/mc/pojos/McOptsContent.java	(.../McOptsContent.java)	(revision b3ab9dedd256ee8c388d395b33b12486730b2f2c)
@@ -32,7 +32,7 @@
  * 
  * @author Ozgur Demirtas
  */
-public class McOptsContent implements Serializable, Comparable {
+public class McOptsContent implements Serializable, Comparable<McOptsContent> {
 
     /** identifier field */
     private Long uid;
@@ -124,8 +124,7 @@
 	this.mcQueContentId = mcQueContentId;
     }
 
-    public int compareTo(Object o) {
-	McOptsContent optContent = (McOptsContent) o;
+    public int compareTo(McOptsContent optContent) {
 	// if the object does not exist yet, then just return any one of 0, -1, 1. Should not make a difference.
 	if (uid == null)
 	    return 1;
Index: lams_tool_lamc/src/java/org/lamsfoundation/lams/tool/mc/pojos/McQueContent.java
===================================================================
diff -u -r9db7a5bb39fecf9a0f1ae5cf2a9f701d2aa1532f -rb3ab9dedd256ee8c388d395b33b12486730b2f2c
--- lams_tool_lamc/src/java/org/lamsfoundation/lams/tool/mc/pojos/McQueContent.java	(.../McQueContent.java)	(revision 9db7a5bb39fecf9a0f1ae5cf2a9f701d2aa1532f)
+++ lams_tool_lamc/src/java/org/lamsfoundation/lams/tool/mc/pojos/McQueContent.java	(.../McQueContent.java)	(revision b3ab9dedd256ee8c388d395b33b12486730b2f2c)
@@ -38,7 +38,7 @@
  * 
  * @author Ozgur Demirtas
  */
-public class McQueContent implements Serializable, Comparable {
+public class McQueContent implements Serializable, Comparable<McQueContent> {
 
     /** identifier field */
     private Long uid;
@@ -207,8 +207,7 @@
 	this.feedback = feedback;
     }
 
-    public int compareTo(Object o) {
-	McQueContent queContent = (McQueContent) o;
+    public int compareTo(McQueContent queContent) {
 	// if the object does not exist yet, then just return any one of 0, -1, 1. Should not make a difference.
 	if (mcQueContentId == null)
 	    return 1;
Index: lams_tool_lamc/src/java/org/lamsfoundation/lams/tool/mc/pojos/McQueUsr.java
===================================================================
diff -u -rc369c0326857e08851d03a29d39d4337091f5253 -rb3ab9dedd256ee8c388d395b33b12486730b2f2c
--- lams_tool_lamc/src/java/org/lamsfoundation/lams/tool/mc/pojos/McQueUsr.java	(.../McQueUsr.java)	(revision c369c0326857e08851d03a29d39d4337091f5253)
+++ lams_tool_lamc/src/java/org/lamsfoundation/lams/tool/mc/pojos/McQueUsr.java	(.../McQueUsr.java)	(revision b3ab9dedd256ee8c388d395b33b12486730b2f2c)
@@ -35,7 +35,7 @@
  * 
  * @author Ozgur Demirtas
  */
-public class McQueUsr implements Serializable {
+public class McQueUsr implements Serializable, Comparable<McQueUsr> {
 
     /** identifier field */
     private Long uid;
@@ -191,4 +191,13 @@
 	}
 	return false;
     }
+
+    public int compareTo(McQueUsr other) {
+ 	// if the object does not exist yet, then just return any one of 0, -1, 1. Should not make a difference.
+ 	if (uid == null)
+ 	    return 1;
+ 	else
+ 	    return (int) (uid.longValue() - other.uid.longValue());
+     }
+
 }
Index: lams_tool_lamc/src/java/org/lamsfoundation/lams/tool/mc/pojos/McSession.java
===================================================================
diff -u -rd66da54e1b79ff5493ac331ec290649184965a7e -rb3ab9dedd256ee8c388d395b33b12486730b2f2c
--- lams_tool_lamc/src/java/org/lamsfoundation/lams/tool/mc/pojos/McSession.java	(.../McSession.java)	(revision d66da54e1b79ff5493ac331ec290649184965a7e)
+++ lams_tool_lamc/src/java/org/lamsfoundation/lams/tool/mc/pojos/McSession.java	(.../McSession.java)	(revision b3ab9dedd256ee8c388d395b33b12486730b2f2c)
@@ -37,7 +37,7 @@
  * 
  * @author Ozgur Demirtas
  */
-public class McSession implements Serializable {
+public class McSession implements Serializable, Comparable<McSession> {
 
     public final static String INCOMPLETE = "INCOMPLETE";
 
@@ -237,4 +237,13 @@
 	boolean isUserLeader = (groupLeader != null) && user.getUid().equals(groupLeader.getUid());
 	return isUserLeader;
     }
+    
+    public int compareTo(McSession other) {
+ 	// if the object does not exist yet, then just return any one of 0, -1, 1. Should not make a difference.
+ 	if (uid == null)
+ 	    return 1;
+ 	else
+ 	    return (int) (uid.longValue() - other.uid.longValue());
+     }
+
 }
Index: lams_tool_lamc/src/java/org/lamsfoundation/lams/tool/mc/pojos/McUsrAttempt.java
===================================================================
diff -u -r9db7a5bb39fecf9a0f1ae5cf2a9f701d2aa1532f -rb3ab9dedd256ee8c388d395b33b12486730b2f2c
--- lams_tool_lamc/src/java/org/lamsfoundation/lams/tool/mc/pojos/McUsrAttempt.java	(.../McUsrAttempt.java)	(revision 9db7a5bb39fecf9a0f1ae5cf2a9f701d2aa1532f)
+++ lams_tool_lamc/src/java/org/lamsfoundation/lams/tool/mc/pojos/McUsrAttempt.java	(.../McUsrAttempt.java)	(revision b3ab9dedd256ee8c388d395b33b12486730b2f2c)
@@ -35,7 +35,7 @@
  * 
  * @author Ozgur Demirtas
  */
-public class McUsrAttempt implements Serializable {
+public class McUsrAttempt implements Serializable, Comparable<McUsrAttempt> {
 
     private static final long serialVersionUID = 4514268732673337338L;
 
@@ -240,4 +240,12 @@
 	return getMark();
     }
 
+    public int compareTo(McUsrAttempt other) {
+ 	// if the object does not exist yet, then just return any one of 0, -1, 1. Should not make a difference.
+ 	if (uid == null)
+ 	    return 1;
+ 	else
+ 	    return (int) (uid.longValue() - other.uid.longValue());
+     }
+
 }
Index: lams_tool_laqa/src/java/org/lamsfoundation/lams/tool/qa/QaQueUsr.java
===================================================================
diff -u -r629b2631320321b57015e15be850e7c6b747225f -rb3ab9dedd256ee8c388d395b33b12486730b2f2c
--- lams_tool_laqa/src/java/org/lamsfoundation/lams/tool/qa/QaQueUsr.java	(.../QaQueUsr.java)	(revision 629b2631320321b57015e15be850e7c6b747225f)
+++ lams_tool_laqa/src/java/org/lamsfoundation/lams/tool/qa/QaQueUsr.java	(.../QaQueUsr.java)	(revision b3ab9dedd256ee8c388d395b33b12486730b2f2c)
@@ -40,7 +40,7 @@
  * 
  * Represents tool users.
  */
-public class QaQueUsr implements Serializable, Nullable {
+public class QaQueUsr implements Serializable, Nullable, Comparable<QaQueUsr> {
 
     private static final long serialVersionUID = -6768077344827699440L;
 
@@ -234,4 +234,13 @@
     public void setLearnerFinished(boolean learnerFinished) {
 	this.learnerFinished = learnerFinished;
     }
+    
+    public int compareTo(QaQueUsr user) {
+	if (user.getUid() != null && uid != null) {
+	    return user.getUid().compareTo(uid) * -1;
+	} else {
+	    return 1;
+	}
+    }
+
 }
Index: lams_tool_vote/src/java/org/lamsfoundation/lams/tool/vote/pojos/VoteQueContent.java
===================================================================
diff -u -r5b17b810b5302c90b2daf6a5866bf4f6e85bef6a -rb3ab9dedd256ee8c388d395b33b12486730b2f2c
--- lams_tool_vote/src/java/org/lamsfoundation/lams/tool/vote/pojos/VoteQueContent.java	(.../VoteQueContent.java)	(revision 5b17b810b5302c90b2daf6a5866bf4f6e85bef6a)
+++ lams_tool_vote/src/java/org/lamsfoundation/lams/tool/vote/pojos/VoteQueContent.java	(.../VoteQueContent.java)	(revision b3ab9dedd256ee8c388d395b33b12486730b2f2c)
@@ -32,7 +32,7 @@
  * 
  * @author Ozgur Demirtas
  */
-public class VoteQueContent implements Serializable, Comparable {
+public class VoteQueContent implements Serializable, Comparable<VoteQueContent> {
 
     /** identifier field */
     private Long uid;
@@ -106,8 +106,7 @@
 	return new ToStringBuilder(this).append("uid", getUid()).toString();
     }
 
-    public int compareTo(Object o) {
-	VoteQueContent queContent = (VoteQueContent) o;
+    public int compareTo(VoteQueContent queContent) {
 	// if the object does not exist yet, then just return any one of 0, -1, 1. Should not make a difference.
 	if (uid == null)
 	    return 1;
Index: lams_tool_vote/src/java/org/lamsfoundation/lams/tool/vote/pojos/VoteQueUsr.java
===================================================================
diff -u -r96866054a8598fbe1b6719c40ea9a5ed898f5daf -rb3ab9dedd256ee8c388d395b33b12486730b2f2c
--- lams_tool_vote/src/java/org/lamsfoundation/lams/tool/vote/pojos/VoteQueUsr.java	(.../VoteQueUsr.java)	(revision 96866054a8598fbe1b6719c40ea9a5ed898f5daf)
+++ lams_tool_vote/src/java/org/lamsfoundation/lams/tool/vote/pojos/VoteQueUsr.java	(.../VoteQueUsr.java)	(revision b3ab9dedd256ee8c388d395b33b12486730b2f2c)
@@ -37,7 +37,7 @@
  * 
  * @author Ozgur Demirtas
  */
-public class VoteQueUsr implements Serializable {
+public class VoteQueUsr implements Serializable, Comparable<VoteQueUsr> {
 
     private static final long serialVersionUID = 7303944502340276133L;
 
@@ -193,4 +193,13 @@
     public void setFinalScreenRequested(boolean finalScreenRequested) {
         this.finalScreenRequested = finalScreenRequested;
     }
+    
+    public int compareTo(VoteQueUsr other) {
+	// if the object does not exist yet, then just return any one of 0, -1, 1. Should not make a difference.
+	if (uid == null)
+	    return 1;
+	else
+	    return (int) (uid.longValue() - other.uid.longValue());
+    }
+
 }
Index: lams_tool_vote/src/java/org/lamsfoundation/lams/tool/vote/pojos/VoteSession.java
===================================================================
diff -u -r96866054a8598fbe1b6719c40ea9a5ed898f5daf -rb3ab9dedd256ee8c388d395b33b12486730b2f2c
--- lams_tool_vote/src/java/org/lamsfoundation/lams/tool/vote/pojos/VoteSession.java	(.../VoteSession.java)	(revision 96866054a8598fbe1b6719c40ea9a5ed898f5daf)
+++ lams_tool_vote/src/java/org/lamsfoundation/lams/tool/vote/pojos/VoteSession.java	(.../VoteSession.java)	(revision b3ab9dedd256ee8c388d395b33b12486730b2f2c)
@@ -36,7 +36,7 @@
  * 
  * @author Ozgur Demirtas
  */
-public class VoteSession implements Serializable {
+public class VoteSession implements Serializable, Comparable<VoteSession> {
 
     public final static String INCOMPLETE = "INCOMPLETE";
 
@@ -231,4 +231,14 @@
     public void setGroupLeader(VoteQueUsr groupLeader) {
 	this.groupLeader = groupLeader;
     }
+    
+    public int compareTo(VoteSession other) {
+	// if the object does not exist yet, then just return any one of 0, -1, 1. Should not make a difference.
+	if (uid == null)
+	    return 1;
+	else
+	    return (int) (uid.longValue() - other.uid.longValue());
+    }
+
+
 }
Index: lams_tool_vote/src/java/org/lamsfoundation/lams/tool/vote/pojos/VoteUsrAttempt.java
===================================================================
diff -u -r9afb93ea36dcedb5db374cacb84b3c4a3d30465c -rb3ab9dedd256ee8c388d395b33b12486730b2f2c
--- lams_tool_vote/src/java/org/lamsfoundation/lams/tool/vote/pojos/VoteUsrAttempt.java	(.../VoteUsrAttempt.java)	(revision 9afb93ea36dcedb5db374cacb84b3c4a3d30465c)
+++ lams_tool_vote/src/java/org/lamsfoundation/lams/tool/vote/pojos/VoteUsrAttempt.java	(.../VoteUsrAttempt.java)	(revision b3ab9dedd256ee8c388d395b33b12486730b2f2c)
@@ -35,7 +35,7 @@
  * 
  * @author Ozgur Demirtas
  */
-public class VoteUsrAttempt implements Serializable {
+public class VoteUsrAttempt implements Serializable, Comparable<VoteUsrAttempt> {
 
     /** identifier field */
     private Long uid;
@@ -222,4 +222,12 @@
 	this.visible = visible;
     }
 
+    public int compareTo(VoteUsrAttempt other) {
+	// if the object does not exist yet, then just return any one of 0, -1, 1. Should not make a difference.
+	if (uid == null)
+	    return 1;
+	else
+	    return (int) (uid.longValue() - other.uid.longValue());
+    }
+
 }