text: class CheckBox extends React.Component{
      constructor(props){
          super(props);
  
          this.handleChange = this.handleChange.bind(this);
      }
  
      handleChange(e){
          if(e.target.checked)
              this.props.onValueChange(e.target.value);
          else
              this.props.onValueChange(0);
      }
  
      render(){
          return (
              <div className="form-check">
                  <input 
                      onChange={this.handleChange}
                      className="form-check-input" 
                      value={this.props.value} 
                      type="checkbox" 
                      checked={this.props.checked == this.props.value}
                      id={this.props.id}
                  />
                  <label className="form-check-label" htmlFor={this.props.id}>{this.props.label}</label>
              </div>
          );
      }
  }
  