# ModifyVDL

Changes one or more attributes of a VDL.

### Synopsis

`Err ModifyVDL (Item vdlItem,TagArg *vdlTags)
Err ModifyVDLVA (Item vdlItem,uint32 vdlTags,...)`

### Description

This call changes one or more attributes of a VDL. When executed, it looks through each entry of the VDL for opcodes, and then changes the specified attributes in each opcode (if they need changing). This means that `ModifyVDL()` affects the entire VDL, regardless of its type. It works equally well on simple VDLs and custom VDLs.

This is a preliminary implementation of `ModifyVDL()`. Future implementations will include the ability to modify individual VDL entries.

### Arguments

vdlItem
  Item number of the VDL to be modified.

vdlTags
  Pointer to the array of TagArgs used to specify the modifications to the VDL.

### Return Value

The call returns a 0 if successful or an error code (a negative value) if an error occurs.

### Implementation

Folio call implemented in Graphics folio V21.

### Associated Files

graphics.h, graphics.lib

### See Also

``SubmitVDL`(), SetVDL(), DeleteVDL()`