text: function Credit(){
    var BacktoMenuClicked = function(){
      game.state.start('StartPage');
    }
    this.create = function(){
      // 배경
      background = game.add.sprite(0,0,'credit_screen');
      background.width = game.scale.width;
      background.height =game.scale.height;
  
      var BacktoMenuButton = game.add.button(game.world.centerX,700,
        'title_button',BacktoMenuClicked,this,1,2,0);
      BacktoMenuButton.anchor.set(0.5);
      BacktoMenuButton.scale.setTo(5);
      var BacktoMenuButtonText = game.add.text(BacktoMenuButton.centerX,BacktoMenuButton.centerY+5,'메뉴로 돌아가기',
      {font:"40px Ariel", fill:"#ffffff",align:"center"});
      BacktoMenuButtonText.stroke = '#4C4C4C';
      BacktoMenuButtonText.strokeThickness = 10;
      BacktoMenuButtonText.anchor.set(0.5);
    }
  }
  