Максим js

var bg = document.getElementById('bb');
         document.getElementById('gg').addEventListener("mouseover",
         function(){bg.style.width = 50 + "%", bg.style.height = 50 + "%";
          this.addEventListener("mouseout", function(){bg.style.width = "" , bg.style.height = "";});

});

var bh =  document.getElementById('qq');
          document.getElementById('gg').addEventListener("mouseover",
           function(){bh.style.width = 50 + "%", bh.style.height = 50 + "%";
           this.addEventListener("mouseout", function(){bh.style.width = "" , bh.style.height = "" ;});
});

var bj =  document.getElementById('ee');
          document.getElementById('gg').addEventListener("mouseover",
           function(){bj.style.width = 50 + "%", bj.style.height = 50 + "%";
           this.addEventListener("mouseout", function(){bj.style.width = "" , bj.style.height = "" ;});
});

var bk =  document.getElementById('ww');
          document.getElementById('gg').addEventListener("mouseover",
           function(){bk.style.width = 50 + "%", bk.style.height = 50 + "%";
           this.addEventListener("mouseout", function(){bk.style.width = "" , bk.style.height = "" ;});
});

добился желаемого эффекта созданием переменной на каждый изменяемый объект, с указанием id желаемой кнопки.