vue中使用sessionStorage记住密码功能

<el-form>
 <div class="rightLoginContent">
    <div class="passWordMain">
      <input type="text" placeholder="用户名" v-model="inpUser" id="inpUser" @change="checkusername" autofocus>
      <i class="ico iconfont icon-xingmingyonghumingnicheng"></i>
    </div>
    <div class="passWordMain marginbottom10">
      <input type="password" placeholder="密码" id="passwordUser" v-model="passwordUser" @change="checkusername" @keyup.enter="loginFun"> 
      <i class="ico iconfont icon-loginmima"></i>
      <div class="prompt" v-show="msgifshow">{{errormsg}}
       <i class="ico iconfont icon-cuowu"></i>
      </div>
    </div>
    <div class="rememberPwd">
     <input type="checkbox" id="rememberPwd" v-model="pwdChecked" @change="savePwd">
      记住密码
    </div>
    <div class="loginBtn stopbuttonLogin" v-show="showlogins">登录</div>
    <div class="loginBtn" @click="loginFun" v-show="showlogines">登录</div>
  </div>
 </el-form>

methods:{
   savePwd:function(){
     var checkboxStatus=this.pwdChecked;
     var inpUser=document.getElementById("inpUser").value;
     var passwordUser=document.getElementById("passwordUser").value;
     if(checkboxStatus==true){
       sessionStorage.setItem(inpUser,passwordUser);
     }
     else{
      sessionStorage.removeItem(inpUser);
     }
   },
   checkusername:function(){
    var inpUser=document.getElementById("inpUser").value;
    var passwordUser=document.getElementById("passwordUser").value;
    /*console.log("inpUser",inpUser);*/
    //从sessionstory中取值
    var sessionipUser=sessionStorage.getItem(inpUser);
    if(""!=sessionipUser && sessionipUser !=null){
     this.passwordUser=sessionipUser;
    }
    if(inpUser=='' || inpUser==null){
     this.showlogins=true;
     this.showlogines=false;
    }else if(passwordUser==''|| passwordUser==null){
     this.showlogins=true;
     this.showlogines=false;
    }
    else{
     this.showlogins=false;
     this.showlogines=true;
      this.buttnLogin=true;
    }
   }