support keep

@@ -65,6 +65,7 @@ function Dialog(options) {
         that.$mask = createMask();
     }
     that.$el = createDialog(opt);
+    that.opt = opt;
 
     // 绑定x关闭事件
     that.$el.find('.close').click(function() {
@@ -87,7 +88,13 @@ function Dialog(options) {
 
 Dialog.prototype.close = function() {
     this.$mask && this.$mask.addClass('hide');
-    this.$el.remove();
+
+    // keep参数保持dialog不被remove而只是隐藏
+    if (this.opt.keep) {
+        this.$el.addClass('hide');
+    } else {
+        this.$el.remove();
+    }
 
     return this;
 };