add: addAutoOption for auto key options

index.js

@@ -207,6 +207,25 @@ Message.prototype.body = "";
 Message.prototype.footer = "Powered by Lottus";
 
 
+Message.prototype.addAutoOption = function addAutoOption(label, next, params){
+    if(!this.form){
+        this.form = {options: new Map()};
+    }
+
+    if(!this.form.options){
+        this.form.options = new Map();
+    }
+
+    let key = this.form.options.size + 1;
+
+    if(!label){
+        throw new Error("Argument label cannot be null nor empty");
+    }
+
+    this.form.options.set(key.toString(), {label, next, params});
+}
+
+
 Message.prototype.addOption = function addOption(key, label, next, params){
     if(!this.form){
         this.form = {options: new Map()};