function archive_all(testOnly) {

    messages = $("._5blh")
    console.log("Found", messages.length, "messages on messsenger.");
    if (!testOnly) {
        for (i = 0; i < messages.length; i++) {
            try {
                messages[i].click()// open dialog
                $("li:contains('Archive')").last().click()
            }
            catch (TypeError) {
                console.log("TypeError")
            }
        }
    }
}