diff --git a/erpnext/accounts/doctype/pos_setting/pos_setting.py b/erpnext/accounts/doctype/pos_setting/pos_setting.py
index 43742ac..6c19882 100755
--- a/erpnext/accounts/doctype/pos_setting/pos_setting.py
+++ b/erpnext/accounts/doctype/pos_setting/pos_setting.py
@@ -34,18 +34,20 @@
 
 
 class DocType:
-  def __init__(self,doc,doclist=[]):
-    self.doc, self.doclist = doc,doclist
+	def __init__(self,doc,doclist=[]):
+		self.doc, self.doclist = doc,doclist
 
-  #--------------------get naming series from sales invoice-----------------
-  def get_series(self):
-    res = sql("select options from `tabDocField` where parent='Sales Invoice' and fieldname = 'naming_series'")
-    return res and cstr(res[0][0]) or ''
-  
-  def validate(self):
-    res = sql("select name, user from `tabPOS Setting` where ifnull(user, '') = '%s' and name != '%s' and company = '%s'" % (self.doc.user, self.doc.name, self.doc.company))
-    if res:
-      if res[0][1]:
-        msgprint("POS Setting '%s' already created for user: '%s' and company: '%s'"%(res[0][0], res[0][1], self.doc.company), raise_exception=1)
-      else:
-        msgprint("Global POS Setting already created - %s for this company: '%s'" % (res[0][0], self.doc.company), raise_exception=1)
+	#--------------------get naming series from sales invoice-----------------
+	def get_series(self):
+		import webnotes.model.doctype
+		docfield = webnotes.model.doctype.get('Sales Invoice')
+		series = [d.options for d in docfield if d.doctype == 'DocField' and d.fieldname == 'naming_series']
+		return series and series[0] or ''
+
+	def validate(self):
+		res = sql("select name, user from `tabPOS Setting` where ifnull(user, '') = '%s' and name != '%s' and company = '%s'" % (self.doc.user, self.doc.name, self.doc.company))
+		if res:
+			if res[0][1]:
+				msgprint("POS Setting '%s' already created for user: '%s' and company: '%s'"%(res[0][0], res[0][1], self.doc.company), raise_exception=1)
+		else:
+			msgprint("Global POS Setting already created - %s for this company: '%s'" % (res[0][0], self.doc.company), raise_exception=1)
diff --git a/erpnext/buying/doctype/purchase_common/purchase_common.js b/erpnext/buying/doctype/purchase_common/purchase_common.js
index a8948ff..3ec6977 100644
--- a/erpnext/buying/doctype/purchase_common/purchase_common.js
+++ b/erpnext/buying/doctype/purchase_common/purchase_common.js
@@ -268,7 +268,7 @@
 var is_item_table = function(doc,cdt,cdn) {
 	// Step 1 :=>Get all childrens/ rows from Detail Table
 	var cl = getchildren(tname, doc.name, fname);
-	// Step 2 :=> If there are no rows then set validated = false, I hope this will stop further execution of code.
+	// Step 2 :=> If there are no rows then set validated = false, this will stop further execution of code.
 	if (cl.length == 0) {
 		alert("There is no item in table"); validated = false;
 	}