How can I select multiple itens in select (combobox) using javascript?

[vehuel]

I have a select multiple (combobox) in a form and I need to select, using javascript, more than one item in this select. How can I do this?

[PLA]

I have a select multiple (combobox) in a form and I need to select, using javascript, more than one item in this select. How can I do this?

If it is a select multiple it should be a listbox and not a combobox.

use

form.select.options[i].selected = true;

i is the index in the list you want to select (0 based)