Note: After saving, you have to bypass your browser's cache to see the changes. Google Chrome, Firefox, Microsoft Edge and Safari: Hold down the ⇧ Shift key and click the Reload toolbar button. For details and instructions about other browsers, see Wikipedia:Bypass your cache.
var request
if (wgPageName.substr(0, 10) == "User_talk:" && window.location.toString().indexOf("action=edit") > 0) {
    if (window.XMLHttpRequest) {
        request = new XMLHttpRequest();
        requesttype = "Mozilla"
    }
    else if (window.ActiveXObject) {
        request = new ActiveXObject("Microsoft.XMLHTTP")
        requesttype = "MSIE"
    }

    if (request) {
        request.onreadystatechange = documentDone;
        request.open("GET", "/w/query.php?format=xml&what=revisions&titles="+wgPageName+"&rvlimit=5&rvcomments", true)
        if (requesttype == "MSIE")
            request.send()
        else
            request.send(null)
    }
}
function documentDone() {
    if (request.readyState == 4 && request.status == 200) {
        mydocument = request.responseXML.documentElement
        stuff = "Last five edits: <ul>"
        for (i = 0; i < 5; i++) {
            if (mydocument.getElementsByTagName("rv")[i]) {
	        stuff = stuff + "<li>" + mydocument.getElementsByTagName("rv")[i].getAttribute("user") + " &mdash; " + mydocument.getElementsByTagName("rv")[i].getAttribute("timestamp") + " &mdash; " + mydocument.getElementsByTagName("rv")[i].getAttribute("comment")
            }
        }
        stuff = stuff + "</ul>"
        document.getElementById("toolbar").innerHTML = stuff + document.getElementById("toolbar").innerHTML
    }
}