#include<ie.au3>
$handle = WinGetHandle("百度一下,你就知道 - Windows Internet Explorer")
$oIE = _IEAttach($handle, "HWND")
$oinputs = _IETagNameGetCollection($oIE, "input")
For $oInput In $oinputs
If $oInput.value = "百度一下" Then
_IEAction($oInput, "click")
EndIf
Next