Control ID

Every control that you create on a page gets a unique ID.  This ID is used when you want to access the control from script, either to retrieve values or set parameters.  When you create a new control, an ID is automatically generated for it, however, these ID's are just numbered sequentially and thus not particularly user friendly.  For controls that you want to access from script, we recommend renaming the ID to something more appropriate, which you can do from any of the control's properties window.  The new ID must be unique, and also must start with a letter and contain only letters, numbers or the underscore.