Required library edition:
Required library file: dhtmlxtoolbar.js

adds a select button to webbar

• id - (string) id of a select button.
• pos - (integer) position of a select button.
• text - (string) text for a select button (null for no text).
• opts - (array) listed options for a select button.
• imgEnabled - (string) image for enabled state (null for no image).
• imgDisabled - (string) image for desabled state (null for no image).
• renderSelect - (“true” or “disabled”) if the parameter is set to true a button 'remembers' the selected item and keeps it selected on the next opening. Optional, by default is true.
• openAll - (boolean) if the parameter is set to true you can open the dropdown list by clicking both on the label and arrow of a button. If the parameter is set to false the dropdown list can be opened just by clicking on the arrow. Optional, by default is true.
• maxOpen - (integer) sets the number of items visible at once. The other items can be gotten by scrolling down the dropdown list. Optional.
• mode - (string) sets the select mode, the mode when the button behaves as a drop-down list. Optional and the only possible value is 'select' (that actually enables the mode).

    toolbar.addButtonSelect(id, pos, text, opts, imgEnabled, imgDisabled, renderSelect, openAll, maxOpen, mode);