diff --git a/build/MDEditor.min.js b/build/MDEditor.min.js
index 2f83eb8..909f627 100644
--- a/build/MDEditor.min.js
+++ b/build/MDEditor.min.js
@@ -884,7 +884,7 @@
             "class": "mde_textarea",
             placeholder: "请在这里输入内容"
         });
-        self.preview = _createElement("div", {
+        self.preview_el = _createElement("div", {
             "class": "mde_preview markdown_body"
         });
         self.tools = _createElement("div", {
@@ -896,7 +896,7 @@
         self.btn_preview.innerHTML = "预览";
         self.tools.appendChild(self.btn_preview);
         css(self.textarea, "min-height", opts.minheight + "px");
-        css(self.preview, "min-height", opts.minheight + "px");
+        css(self.preview_el, "min-height", opts.minheight + "px");
     }
     MDEditor.prototype = {
         load: function() {
@@ -904,24 +904,13 @@
             if (box) {
                 if (box.innerHTML !== "") self.opts.value = box.innerHTML.replace(/\&gt\;/g, ">").replace(/\&lt\;/g, "<"), 
                 box.innerHTML = "";
-                box.appendChild(self.preview), box.appendChild(self.tools), box.appendChild(self.textarea);
+                box.appendChild(self.preview_el), box.appendChild(self.tools), box.appendChild(self.textarea);
             }
             self.setMD();
             addEvent(self.btn_preview, "click", function(event) {
-                index = parseInt(self.preview.style.zIndex);
-                if (index === 9) {
-                    self.preview.style.zIndex = 0;
-                    this.innerHTML = "预览";
-                } else {
-                    self.preview.style.zIndex = 9;
-                    this.innerHTML = "编辑";
-                }
-                self.setHTML(self.getMD());
-                css(self.preview, {
-                    height: self.textarea.offsetHeight + "px"
-                });
+                self.preview();
             });
-            css(self.preview, {
+            css(self.preview_el, {
                 height: self.textarea.offsetHeight + "px"
             });
             addEvent(self.textarea, "input propertychange", function(event) {
@@ -936,7 +925,7 @@
                         overflow: "auto"
                     });
                 }
-                css(self.preview, {
+                css(self.preview_el, {
                     height: self.textarea.offsetHeight + "px"
                 });
                 self.opts.value = this.value;
@@ -944,6 +933,21 @@
             });
             return this;
         },
+        preview: function() {
+            var self = this, index = parseInt(self.preview_el.style.zIndex) || 0;
+            if (index === 9) {
+                self.preview_el.style.zIndex = 0;
+                self.btn_preview.innerHTML = "预览";
+            } else {
+                self.preview_el.style.zIndex = 9;
+                self.btn_preview.innerHTML = "编辑";
+            }
+            self.setHTML(self.getMD());
+            css(self.preview_el, {
+                height: self.textarea.offsetHeight + "px"
+            });
+            return this;
+        },
         getMD: function() {
             return this.textarea.value;
         },
@@ -953,10 +957,10 @@
             return this;
         },
         getHTML: function() {
-            if (marked) return marked(this.getMD()); else return this.preview.innerHTML;
+            if (marked) return marked(this.getMD()); else return this.preview_el.innerHTML;
         },
         setHTML: function(val) {
-            if (marked) this.preview.innerHTML = marked(val ? val : this.opts.value);
+            if (marked) this.preview_el.innerHTML = marked(val ? val : this.opts.value);
             return this;
         },
         input: function(evn) {
diff --git a/lib/MDEditor.js b/lib/MDEditor.js
index 0e00868..12c9303 100644
--- a/lib/MDEditor.js
+++ b/lib/MDEditor.js
@@ -131,14 +131,14 @@
             class:"mde_textarea",
             placeholder:"请在这里输入内容"
         });
-        self.preview = _createElement('div',{class:"mde_preview markdown_body"});
+        self.preview_el = _createElement('div',{class:"mde_preview markdown_body"});
         self.tools = _createElement('div',{class:"mde_tools"});
         self.btn_preview = _createElement('i',{class:"btn_preview"});
         self.btn_preview.innerHTML = "预览";
         self.tools.appendChild(self.btn_preview);
 
         css(self.textarea,'min-height',opts.minheight + "px");
-        css(self.preview,'min-height',opts.minheight + "px");
+        css(self.preview_el,'min-height',opts.minheight + "px");
     }
 
     MDEditor.prototype = {
@@ -152,26 +152,15 @@
                         .replace(/\&gt\;/g,'>')
                         .replace(/\&lt\;/g,'<'),
                     box.innerHTML='';
-                box.appendChild(self.preview),
+                box.appendChild(self.preview_el),
                 box.appendChild(self.tools),
                 box.appendChild(self.textarea);
             }
             self.setMD();
 
-            addEvent(self.btn_preview,'click', function(event) {
-                index = parseInt(self.preview.style.zIndex)
-                if(index === 9){
-                    self.preview.style.zIndex = 0
-                    this.innerHTML = "预览"
-                }else{
-                    self.preview.style.zIndex = 9
-                    this.innerHTML = "编辑"
-                }
-                self.setHTML(self.getMD())
-                css(self.preview,{'height':self.textarea.offsetHeight + "px"});
-            });
+            addEvent(self.btn_preview,'click', function(event) {self.preview();});
 
-            css(self.preview,{'height':self.textarea.offsetHeight + "px"});
+            css(self.preview_el,{'height':self.textarea.offsetHeight + "px"});
 
             //实时监听输入框值变化 HTML5事件
             addEvent(self.textarea,'input propertychange', function(event) {
@@ -186,12 +175,25 @@
                         'overflow':"auto"
                     });
                 }
-                css(self.preview,{'height':self.textarea.offsetHeight  + "px"});
+                css(self.preview_el,{'height':self.textarea.offsetHeight  + "px"});
                 self.opts.value = this.value
                 self.callback(event,self.opts)
             });
             return this;
         },
+        preview:function(){
+            var self = this,index = parseInt(self.preview_el.style.zIndex) || 0;
+            if(index === 9){
+                self.preview_el.style.zIndex = 0
+                self.btn_preview.innerHTML = "预览"
+            }else{
+                self.preview_el.style.zIndex = 9
+                self.btn_preview.innerHTML = "编辑"
+            }
+            self.setHTML(self.getMD())
+            css(self.preview_el,{'height':self.textarea.offsetHeight + "px"});
+            return this;
+        },
         /**
          * [getMD 获取markdown的字符串]
          * @return {[type]} [返回markdown字符串]
@@ -213,13 +215,13 @@
          */
         getHTML:function(){
             if(marked) return marked(this.getMD());
-            else return this.preview.innerHTML
+            else return this.preview_el.innerHTML
         },
         /**
          * [setHTML 设置预览的HTML]
          */
         setHTML:function(val){
-            if(marked) this.preview.innerHTML = marked(val?val:this.opts.value);
+            if(marked) this.preview_el.innerHTML = marked(val?val:this.opts.value);
             return this;
         },
         /**