edit

app/models/batch_line_item.rb

@@ -24,12 +24,13 @@ class BatchLineItem < ApplicationRecord
 	    find_lookup=Lookup.find_by_name('generate_serial_no')
 	    if !find_lookup.nil?
 	    	max_value=find_lookup.max_value
-	    	max_value=max_value +1
 	    	prefix=find_lookup.prefix
-	    	max_length=find_lookup.max_length	    	
+	    	max_length=find_lookup.max_length	
+
+	    	max_value=max_value +1	    	
 	    	sufix_len=max_length-prefix.length 
 	    	sufix_str="0" * sufix_len	      
-	    	value_len= max_value.to_s.length	 
+	     	 
 	    	start=0
 	    	ends=sufix_len-value_len-1
 	    	sufix_str= sufix_str[start..ends]
@@ -38,6 +39,13 @@ class BatchLineItem < ApplicationRecord
 
 	    	serial_no=prefix_str.to_s+sufix_str+max_value.to_s	    	
 	    	return serial_no
+	    else
+	    	lookup= Lookup.new
+		  	lookup.name="generate_serial_no"
+		  	lookup.max_value=0
+		  	lookup.prefix='0000'
+		  	lookup.max_length=16
+		  	lookup.save	
 	    end
 	end
 	def self.to_csv(user_id)