diff --git a/erpnext/controllers/accounts_controller.py b/erpnext/controllers/accounts_controller.py
index 86f5d53..7faf792 100644
--- a/erpnext/controllers/accounts_controller.py
+++ b/erpnext/controllers/accounts_controller.py
@@ -1163,8 +1163,13 @@
 			deleted_children.append(item)
 
 	for d in deleted_children:
-		if parent.doctype == "Sales Order" and flt(d.delivered_qty):
-			frappe.throw(_("Row #{0}: Cannot delete item {1} which has already been delivered").format(d.idx, d.item_code))
+		if parent.doctype == "Sales Order":
+			if flt(d.delivered_qty):
+				frappe.throw(_("Row #{0}: Cannot delete item {1} which has already been delivered").format(d.idx, d.item_code))
+			if flt(d.work_order_qty):
+				frappe.throw(_("Row #{0}: Cannot delete item {1} which has work order assigned to it.").format(d.idx, d.item_code))
+			if flt(d.ordered_qty):
+				frappe.throw(_("Row #{0}: Cannot delete item {1} which is assigned to customer's purchase order.").format(d.idx, d.item_code))
 
 		if parent.doctype == "Purchase Order" and flt(d.received_qty):
 			frappe.throw(_("Row #{0}: Cannot delete item {1} which has already been received").format(d.idx, d.item_code))
diff --git a/erpnext/selling/doctype/sales_order/sales_order.js b/erpnext/selling/doctype/sales_order/sales_order.js
index 2dae0d8..cb016a1 100644
--- a/erpnext/selling/doctype/sales_order/sales_order.js
+++ b/erpnext/selling/doctype/sales_order/sales_order.js
@@ -12,7 +12,8 @@
 			'Material Request': 'Material Request',
 			'Purchase Order': 'Purchase Order',
 			'Project': 'Project',
-			'Payment Entry': "Payment"
+			'Payment Entry': "Payment",
+			'Work Order': "Work Order"
 		}
 		frm.add_fetch('customer', 'tax_id', 'tax_id');