tate_class = 'tate';
yoko_class = 'yoko';
function tate(){
   document.getElementById('page').className = tate_class;
   document.getElementById('bottun').innerText = '������';
   document.getElementById('bottun').href = 'javascript:yoko();';
}
function yoko(){
   document.getElementById('page').className = yoko_class;
   document.getElementById('bottun').innerText = '�c����';
   document.getElementById('bottun').href = 'javascript:tate();';
}