diff --git a/gscn_drv.h b/gscn_drv.h
index fe851c9..c52dc66 100644
--- a/gscn_drv.h
+++ b/gscn_drv.h
@@ -54,6 +54,7 @@ public:
 	virtual void setdecodepixtype(int twpixtype)= 0;
 	virtual UINT32 get_ErrorCode() = 0;
 	virtual void Set_ErrorCode(UINT32 value) = 0;
+	virtual int get_scanned_num() = 0;
 };