diff --git a/src/StringPrototype.js b/src/StringPrototype.js
new file mode 100644
index 00000000..851d4953
--- /dev/null
+++ b/src/StringPrototype.js
@@ -0,0 +1,18 @@
+if (String.prototype.replaceAll === undefined) {
+  String.prototype.replaceAll = function (before, after) {
+    let res = new String(), matched = 0;
+    for (let i = 0; i < this.length; i += 1) {
+      if (this[i] == before[matched]) {
+        matched += 1;
+        if (matched == before.length) {
+          res += after;
+          matched = 0;
+        }
+      } else {
+        matched = 0;
+        res += this[i];
+      }
+    }
+    return res;
+  };
+}
\ No newline at end of file
diff --git a/src/components/problem/content.vue b/src/components/problem/content.vue
index 715ad368..3cfa6a96 100644
--- a/src/components/problem/content.vue
+++ b/src/components/problem/content.vue
@@ -1,7 +1,7 @@
 <template>
   <div id="problem-view">
     <div id="content">
-      <div id="problem-content">
+      <div id="problem-content" v-loading="problemLoading">
         <div v-if="!isWider" id="full-screen-button" @click="full_screen()">
           Expand
           <i class="el-icon-arrow-right"></i>
@@ -85,7 +85,8 @@ export default {
       enable: true,
       hidden: false,
       time: '-',
-      memery: '-'
+      memery: '-',
+      problemLoading: true
     };
   },
   methods: {
@@ -101,6 +102,7 @@ export default {
           this.memery = data.memory_limit / 1000;
           this.time = data.time_limit;
           this.hidden = !data.enabled;
+          this.problemLoading = false;
         })
         .catch(err => {
           if(err.request.status === 404) {
diff --git a/src/main.js b/src/main.js
index 29e7e7d3..0f5b1930 100644
--- a/src/main.js
+++ b/src/main.js
@@ -35,6 +35,8 @@ import './assets/css/fontstyle.css';
 import './assets/css/basic.css';
 import('./loader/load');
 
+import './StringPrototype';
+
 Vue.config.productionTip = false;
 
 new Vue({