Required library edition:
Required library file: dhtmlxtoolbar.js

adds a select button to webbar

• id - id of a select button
• pos - position of a select button
• text - text for a select button (null for no text)
• opts - listed options for a select button
• imgEnabled - image for enabled state (null for no image)
• imgDisabled - image for desabled state (null for no image)

    toolbar.addButtonSelect(id, pos, text, opts, imgEnabled, imgDisabled);