old_contents: import React, { Component } from 'react';
  import './App.css';
  
  class App extends Component {
    constructor(props) {
      super(props);
      this.state = {value: ''};
      
      this.handleChange = this.handleChange.bind(this);
      this.handleSubmit = this.handleSubmit.bind(this);
    }
  
    handleChange(event) {
      this.setState({value: event.target.value});
    }
  
    handleSubmit(event) {
      alert('Please wait');
      event.preventDefault();
    }
  
  
    render() {
      return (
        <div className="App">
          <header className="App-header">
              <h1 className="App-title">welcome to malusers</h1>
          </header>
  
          <div className="App-intro">
              <form onSubmit={this.handleSubmit} >
              <input type="text" placeholder="User name" value={this.state.value} onChange={this.handleChange}/>
              <input type="submit" value="Submit"/>
              </form>
          </div>
        </div>
      );
    }
  }
  
  export default App;
  
new_contents: import React, { Component } from 'react';
  import './App.css';
  
  class App extends Component {
    constructor(props) {
      super(props);
      this.state = { value: '' };
  
      this.handleChange = this.handleChange.bind(this);
      this.handleSubmit = this.handleSubmit.bind(this);
    }
  
    handleChange(event) {
      this.setState({ value: event.target.value });
    }
  
    handleSubmit(event) {
      alert('Please wait');
      event.preventDefault();
    }
  
    render() {
      return (
        <div className="App">
          <header className="App-header">
            <h1 className="App-title">welcome to malusers</h1>
          </header>
  
          <div className="App-intro">
            <form onSubmit={this.handleSubmit}>
              <input
                type="text"
                placeholder="User name"
                value={this.state.value}
                onChange={this.handleChange}
              />
              <input type="submit" value="Submit" />
            </form>
          </div>
        </div>
      );
    }
  }
  
  export default App;
  
subject: Fix prettier errors