diff --git a/application/models/purchaseorder_model.php b/application/models/purchaseorder_model.php
index ee05efe9..86e6e993 100755
--- a/application/models/purchaseorder_model.php
+++ b/application/models/purchaseorder_model.php
@@ -464,7 +464,7 @@ function GetPOType($ReqNo)
      * This function is used to add New Purchase order to  the system
     
      */
-    function addPOMaster($POMaster)
+    function addPOMaster($POMaster,$POType,$POSubtype)
 	{
 			$this->db->trans_start();
 			$this->db->insert('T_PurchaseOrder_Master', $POMaster);        
@@ -473,9 +473,9 @@ function GetPOType($ReqNo)
 			// print_r($this->db->last_query());		
 			if($insert_id>0)
 			{
-				$subQuery = 'select max(PONO) as PONO from T_PurchaseOrder_Master';   
+				$subQuery = 'select max(PONO) as PONO from T_PurchaseOrder_Master where POType=? and POSubType=?';   
           
-				$query = $this->db->query($subQuery);
+				$query = $this->db->query($subQuery,array($POType,$POSubtype));
         
 				return $query->result_array();
 			}