--- a/s4-main.js	Tue Jun 30 08:52:20 2020 +0900
+++ b/s4-main.js	Tue Jun 30 10:55:43 2020 +0900
@@ -72,15 +72,59 @@
 	    u.checked = !u.checked;
 	}
     }
-    function helpMarkdown(e) {
-	//alert(e.keyCode);
-	if (e.keyCode == 13) {
+    function renumberOL(str, start) {
+	var stra = str.split("\n");
+		
+	for (var i=1; i<stra.length; i++) {
+	    if (stra[i].match(/^[1-9][0-9]*\. /)) {
+		let orig=stra[i];
+		stra[i] = (++start)+". "+RegExp.rightContext;
+	    } else if (stra[i].match(/^  /)) {
+		continue;
+	    } else
+		break;
+	}
+	return stra.join("\n");
+    }
+    function submitThisForm(input) {
+	for (var elm=input.parentNode; elm; elm = elm.parentNode) {
+	    if (elm.nodeName.match(/form/i)) {
+		elm.submit();
+		return true;
+	    }
+	}
+	return false;
+    }
+    function helpMarkdownBS(e) {
+	var area = e.target, pos = area.selectionStart, text = area.value;
+	if (area.selectionStart != area.selectionEnd) return;
+	if (pos<2) return;
+	if (text.substr(pos-1, 2)=="\n\n") return;
+	var bol  = text.lastIndexOf("\n", pos-1),
+	    eol  = text.indexOf("\n", pos);
+	if (bol<=0 || bol==eol) return;
+	var thisline = text.substring(bol+1, eol==-1 ? text.length : eol);
+	thisline = text.substring(bol+1, pos);
+	if (thisline == "* ") {
+	    area.setSelectionRange(pos-2, pos);
+	} else if (thisline.match(/^[1-9][0-9]*\. $/)) {
+	    area.setSelectionRange(pos-RegExp.lastMatch.length, pos);
+	}
+    }
+    function helpMarkdownEnter(e) {
+	if (e.keyCode == 13 && !e.shiftKey) {
+	    if (e.metaKey && submitThisForm(e.target)) {
+		e.preventDefault();
+		return;
+	    }
 	    var area = e.target;
 	    var pos  = area.selectionStart, text = area.value;
 	    if (pos==0) return;
 	    var last = text.lastIndexOf("\n", pos-1);
-	    var rest = text.substring(pos);
-	    var line = last ? text.substring(last+1) : text;
+	    var rest = text.substring(pos), rest0=rest;
+	    var line = last ? text.substring(last+1, pos) : text;
+	    var next = rest.substring(rest.indexOf("\n"))||rest;
+	    next=next.substring(1);
 	    var tail = text.substring(pos-2, pos), br = (tail=="  ");
 	    var add  = "", offset = 1;
 	    if (line.startsWith("* ")) {
@@ -90,26 +134,68 @@
 		    add = "  " + "\n" + add;
 		}
 	    } else if (line.match(/^([1-9][0-9]*)\. /)) {
-		ln = parseInt(RegExp.$1);
-		add = (ln+1)+". ";
-		offset += add.length;
+		var ln = parseInt(RegExp.$1), nn=ln+1,
+		    len = RegExp.lastMatch.length;
+		add = nn+". ";
+		let toeol = text.substr(pos, text.indexOf("\n"));
 		if (br) {
-		    add = " ".repeat(RegExp.$1.length+2) + "\n" + add;
+		    if (next.startsWith(add)) {
+			add=" ".repeat(len);
+			nn = ln;
+		    } else {
+			add = " ".repeat(len)+ "\n" + add;
+			offset -= len+1;
+		    }
 		}
-	    } else if (line.match(/^\|(  *).+\|/)) {
-		alert("table");
+		if (next.match(/^[1-9][0-9]*\. /))
+		    rest = renumberOL(rest, nn);
+		offset += add.length;
+	    } else if (line.match(/^\|( *).+\|/)) {
 		add = "|" + RegExp.$1 + " |";
 		offset += add.length-2;
 	    } else {
 		return;
 	    }
 	    e.preventDefault();
-	    area.value = text.substring(0, pos) + "\n" + add + rest;
+	    if (!document.execCommand("insertText", false, "\n"+add)) {
+		//Firefox
+		area.selectionEnd = area.value.length;
+		area.setRangeText("\n"+add+rest);
+		area.selectionEnd = null;
+	    } else {
+		area.selectionEnd = area.value.length;
+		area.setSelectionRange(area.selectionStart, area.value.length);
+		document.execCommand("insertText", false, rest);
+		area.selectionEnd = null;
+		area.focus();
+	    }
+	    area.selectionStart = pos+offset;
+	    return;
+	    if (document.execCommand("insertText", false, "\n"+add)) {
+		//area.setSelectionRange(area.selectionStart, text.length);
+		// alert("rest=["+rest+"], add=["+add+"]");
+		alert(text.substring(pos, area.value.length));
+		if (rest != rest0) {
+		    area.setSelectionRange(pos, area.value.length);
+		    return;
+		    document.execCommand("delete");
+		}
+		document.execCommand("insertText", false, rest);
+	    } else {
+		// Firefox cannot use insertText in textarea...
+		area.value = text.substring(0, pos) + "\n" + add + rest;
+	    }
 	    //area.setSelectionRange(pos+length(add));
 	    area.selectionStart=area.selectionEnd = (pos + offset);
 	    
 	}
     }
+    function helpMarkdown(e) {
+	switch (e.keyCode) {
+	case  8: helpMarkdownBS(e); break;
+	case 13: helpMarkdownEnter(e); break;
+	}
+    }
     /* Init event listeners */
     function addFileInput() {
 	var inpfile = collectElementsByAttr("input", "name", "image");