Index: branches/features/purchaseOrders/grails-app/domain/PurchaseOrder.groovy
===================================================================
--- branches/features/purchaseOrders/grails-app/domain/PurchaseOrder.groovy	(revision 895)
+++ branches/features/purchaseOrders/grails-app/domain/PurchaseOrder.groovy	(revision 896)
@@ -3,5 +3,5 @@
     Supplier supplier
 
-    String comments
+    String comment = ""
     Date ordered
 
@@ -11,5 +11,5 @@
 
     static constraints = {
-        comments(nullable:true)
+        comment(maxSize:255)
         ordered(nullable:true)
     }
Index: branches/features/purchaseOrders/test/unit/PurchaseOrderServiceTests.groovy
===================================================================
--- branches/features/purchaseOrders/test/unit/PurchaseOrderServiceTests.groovy	(revision 895)
+++ branches/features/purchaseOrders/test/unit/PurchaseOrderServiceTests.groovy	(revision 896)
@@ -55,5 +55,5 @@
         def po = pos.getOrCreatePurchaseOrder(params)
 
-        assertThat po.comments, equalTo("Created by test")
+        assertThat po.comment, equalTo("Created by test")
         assertThat po.purchaseOrderNumber.value, equalTo("P1001")
     }
@@ -67,5 +67,5 @@
         def po = pos.getOrCreatePurchaseOrder(params)
 
-        assertThat po.comments, equalTo(null)
+        assertThat po.comment, equalTo("")
         assertThat po.purchaseOrderNumber.value, equalTo("P1003")
     }
@@ -87,5 +87,5 @@
     def createPurchaseOrders(int howMany) {
         for (int i=0; i<howMany; i++) {
-            def po = new PurchaseOrder(comments:"Created by test", supplier:new Supplier())
+            def po = new PurchaseOrder(comment:"Created by test", supplier:new Supplier())
             def pon = PurchaseOrderNumber.list()[i]
             pon.purchaseOrder = po;