better validation message
diff --git a/erpnext/stock/doctype/packing_slip/packing_slip.js b/erpnext/stock/doctype/packing_slip/packing_slip.js
index 69d12eb..9f6b9ff 100644
--- a/erpnext/stock/doctype/packing_slip/packing_slip.js
+++ b/erpnext/stock/doctype/packing_slip/packing_slip.js
@@ -48,7 +48,7 @@
 cur_frm.cscript.validate_case_nos = function(doc) {
 	doc = locals[doc.doctype][doc.name];
 	if(cint(doc.from_case_no)==0) {
-		frappe.msgprint(__("Case No. cannot be 0"))
+		frappe.msgprint(__("The 'From Package No.' field must neither be empty nor it's value less than 1."));
 		frappe.validated = false;
 	} else if(!cint(doc.to_case_no)) {
 		doc.to_case_no = doc.from_case_no;
@@ -124,3 +124,5 @@
 cur_frm.pformat.gross_weight_pkg= function(doc){
 	return '<table style="width:100%">' + make_row('Gross Weight', doc.gross_weight_pkg) + '</table>'
 }
+
+// TODO: validate gross weight field
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