diff --git a/LSL2/STPROC/COMM_WO_REC.txt b/LSL2/STPROC/COMM_WO_REC.txt
index 408f438..b49931f 100644
--- a/LSL2/STPROC/COMM_WO_REC.txt
+++ b/LSL2/STPROC/COMM_WO_REC.txt
@@ -179,15 +179,19 @@ Read:
     MsgUp = Msg(@window, Def)   
     Columns  = 'CASS_NO':@VM:'LOT_NO':@VM:'WAFER_QTY':@VM:'CUST_PART_NO':@VM:'SUB_PART_NO':@VM:'SUB_VEND_CD':@VM:'RX_DTM':@VM:'RX_BY':@VM:'ORDER_ITEM'
     WOMatKeys = Wo_Mat_Services('GetWOMatKeys', WONo)
-    If Error_Services('NoError') then 
-        CassData = WO_Mat_Services('GetWOMatData', WOMatKeys, Columns)
-        If Error_Services('NoError') then
-            Set_Property(@Window:'.CASS_NO', 'ARRAY', CassData)
-            Msg(@window, MsgUp) 
-        end else
-            Msg(@window, MsgUp)        
-            Msg(@Window, '', 'OK', '', 'Process Error':@FM:Error_Services('GetMessage'))
-        end
+    If Error_Services('NoError') then
+    	If (WOMatKeys NE '') then 
+			CassData = WO_Mat_Services('GetWOMatData', WOMatKeys, Columns)
+			If Error_Services('NoError') then
+				Set_Property(@Window:'.CASS_NO', 'ARRAY', CassData)
+				Msg(@window, MsgUp) 
+			end else
+				Msg(@window, MsgUp)        
+				Msg(@Window, '', 'OK', '', 'Process Error':@FM:Error_Services('GetMessage'))
+			end
+		end else
+			Msg(@window, MsgUp)       
+		end
     end else
         Msg(@window, MsgUp)         
         Msg(@Window, '', 'OK', '', 'Process Error':@FM:Error_Services('GetMessage'))