validation for stock and nonstock items in purchase cycle
diff --git a/controllers/buying_controller.py b/controllers/buying_controller.py
index 94e3d56..e167dc5 100644
--- a/controllers/buying_controller.py
+++ b/controllers/buying_controller.py
@@ -45,12 +45,13 @@
 			
 	def validate_stock_or_nonstock_items(self):
 		items = [d.item_code for d in self.doclist.get({"parentfield": self.fname})]
-		if self.stock_items and len(items) > len(self.stock_items):
+		if self.stock_items:
 			nonstock_items = list(set(items) - set(self.stock_items))
-			webnotes.msgprint(_("Stock and non-stock items can not be entered in the same ") + 
-				self.doc.doctype + _(""". You should make separate documents for them.
-				Stock Items: """) + ", ".join(self.stock_items) + _("""
-				Non-stock Items: """) + ", ".join(nonstock_items), raise_exception=1)
+			if nonstock_items:
+				webnotes.msgprint(_("Stock and non-stock items can not be entered in the same ") + 
+					self.doc.doctype + _(""". You should make separate documents for them.
+					Stock Items: """) + ", ".join(self.stock_items) + _("""
+					Non-stock Items: """) + ", ".join(nonstock_items), raise_exception=1)
 				
 		elif items and not self.stock_items:
 			tax_for_valuation = [d.account_head for d in