[proxy]

Код:

; *******************************************************
; Example 1 - Open a browser with the form example, get reference to form, get reference
;               to select element, cycle 10 times selecting options byValue, byText and byIndex
;               Note: You will likely need to scroll down on the page to see the changes
; *******************************************************
;
#include <IE.au3>
$oIE = _IE_Example ("form")
$oForm = _IEFormGetObjByName ($oIE, "ExampleForm")
$oSelect = _IEFormElementGetObjByName ($oForm, "selectExample")
For $i = 1 To 10
    _IEFormElementOptionSelect ($oSelect, "Freepage", 1, "byText")
    Sleep(1000)
    _IEFormElementOptionSelect ($oSelect, "midipage.html", 1, "byValue")
    Sleep(1000)
    _IEFormElementOptionSelect ($oSelect, 0, 1, "byIndex")
    Sleep(1000)
Next

Функции _IE*, справка по UDF (находится в корне папки AutoIt).
Для других браузеров, другие UDF, примерно эти: Opera, FF.
И т.д., поиск по офф форуму.