//<pre><nowiki>

String.prototype.trim = function(){return this.replace(/^\s*|\s*$/g,"")};

if (typeof usersignature == 'undefined') usersignature = ' \~\~\~\~\n';

if (typeof regpages == 'undefined') { // list of all none talk pages
    var regpages = [
    ':Village pump',
    ':Articles for deletion',
    ':Requests for ',
    ':Reference desk',
    ':Deletion review',
    ':Templates for deletion',
    '.*noticeboard.*',
    ':checkuser',
    ':arbitration',
    ':feedback',
    ':page protection',
    'mediation)',
    ':Bot requests',
    ':Help desk',
    ':Editor review',
    ':Adminship survey',
    ':Cleanup',
    ':Miscellany for deletion',
    ':New contributors\' help page',
    ':Media copyright questions'
    ];
} 

    // regarded pages type encoded
if (wgCanonicalNamespace.match(/talk$/i)) var regpages = "";
for (p in regpages) if (wgPageName.indexOf(regpages[p]) != -1){regpages=false; break}

if (!regpages) 
addOnloadHook(function(){
    if (!(window.editform = document.forms['editform'])) return;
    // Add a new checkbox to the Wiki editOptions.
    sigBox = document.createElement("input");
    sigBox.setAttribute('type','checkbox');
    sigBox.setAttribute('name','wpSigning');
    sigBox.setAttribute('id','wpSigning');
    sigBox.setAttribute('checked','checked');
    sigBox.defaultChecked=true;
    neuB = document.createElement("label");
    neuB.appendChild(sigBox);
    neuB.appendChild(document.createTextNode("Sign"));
    neuB.setAttribute('for','wpSigning');
    neuB.setAttribute('title','Sign this edit automatic.');
    
    function setSigBox() { // switch enable box
        if (editform.wpMinoredit.checked) sigBox.setAttribute('disabled','disabled');
        else sigBox.removeAttribute('disabled');
    };

    var txtarea=editform.elements['wpTextbox1'];
    var txtOld=txtarea.value.trim();
    // txtOld_l=txtOld.length
    var txtOldEnd=txtOld.slice(-24);
    var sig = /~{3}/g;

    if (!tNode){
        //editform.insertBefore(neuB, editform.elements['wpWatchthis']); // maybe FIXME: raised an NS_DOM_ERR!
        var tNode = editform.elements['wpMinoredit'].parentNode;  // DOM workaround!?
        tNode.divs = tNode.getElementsByTagName("DIV");
        tNode.divs = tNode.divs.item(tNode.divs.length-1); // last div
        tNode.insertBefore(neuB, tNode.divs);
        setSigBox();
    }
    
    function doSign(event){
        if(editform.onsubmit==''){ // only once!
            removeEvent(editform.wpSave,"click",doSign);
            removeEvent(editform.wpPreview,"click",doSign);
        }
        if(editform.onsubmit=='') removeEvent(editform.wpSave,"click",doSign); // only once!
        if(editform.wpMinoredit.checked || !sigBox.checked) return;
        txtarea.focus();
        var cOld = txtOld.match(/<nowiki>.*?~{3}.*?<\/nowiki>/g); // exception for nowiki
        if (cOld) cOld = cOld.length;
        cNew = txtarea.value.match(sig); if (cNew) cNew = cNew.length;
        if (cNew > cOld){ // if there are a sign, check for true
            var cNew2 = txtarea.value.match(/\{\{subst\:unsig.*?~{3}\}\}/); // exception for Template:unsigned
            cNew -= (cNew2)?cNew2.length:0;
        }
        if(cNew <= cOld){ // if nothing then search a set position
            txt=txtarea.value.trim();
            txtEnd=txt.slice(-24);
            if(txtOldEnd!=txtEnd) return txtarea.value = txt + usersignature;  // aut. underwrite
            else { // post between
                pos = getCaretPos(txtarea);
                pos = txt.indexOf('\n', pos); // go to the post-end
                txtEnds = txt.substr(pos,24).replace(/(^\s*)/,""); // after
                txtpEnds = txt.slice(pos-18,pos); // before
                oldp = txtOld.indexOf(txtEnds);
                if(oldp!=-1 && oldp < pos - 3 && txtOld.indexOf(txtpEnds+RegExp.$1+txtEnds)==-1) // if some added
                    return txtarea.value = txt.slice(0,pos).trim() + usersignature + txt.slice(pos+1);
            }
         // FIXME: then the edit-end is not found!?
        }
        else if(!sig.test(txtOld) || cOld < cNew) return;
        if (event) event=(window.Event)? event.target: event.srcElement;
        if (event.name == 'wpPreview') return; // not for preview
        return editform.onsubmit=new Function("editform.onsubmit='';"
          +"return confirm('No signing was found. Continue anyway?')"); //warn if saving without signature
    };
    addEvent(editform.wpSave,"click", doSign);
    addEvent(editform.wpPreview,"click", doSign);
    addEvent(editform.wpMinoredit,"click", setSigBox);
});

function getCaretPos(txtObj){
    if (txtObj.setSelectionRange) return txtObj.selectionStart; // NS like
    else if(!document.selection) return 0;  // not IE like
    var c="\001", pos=0;
    var range=document.selection.createRange();
    var txt=range.text, dul=range.duplicate();
    dul.moveToElementText(txtObj);
    range.text=txt+c;
    pos=(dul.text.indexOf(c));
    range.moveStart('character',-1);
    range.text="";
    return pos;
};

/* add/removeEvent Original idea by John Resig
 Tweaked by Scott Andrew LePera, Dean Edwards and Peter-Paul Koch
 Fixed for IE by Tino Zijdel (crisp) @date 2005-10 */
function addEvent(obj,type,fn){if(obj.addEventListener){obj.addEventListener(type,fn,false)}else if(obj.attachEvent){var eProp=type+fn;obj["e"+eProp]=fn;obj[eProp]=function(){obj["e"+eProp](window.event)};obj.attachEvent("on"+type,obj[eProp])}else{obj['on'+type]=fn}};
function removeEvent(obj,type,fn){if(obj.removeEventListener){obj.removeEventListener(type,fn,false)}else if(obj.detachEvent){var eProp=type+fn;obj.detachEvent("on"+type,obj[eProp]);obj['e'+eProp]=null;obj[eProp]=null}else{obj['on'+type]=null}};

// *** end *** </nowiki></pre>