function t1_show(){
  if (document.getElementById('t1').style.display == 'none')
  {
    document.getElementById('t1').style.display = 'block';
    document.getElementById('t2').style.display = 'none';
    document.getElementById('a1').style.color= '#1a4aa3';
    document.getElementById('a2').style.color= '#000000';
    document.getElementById('b1_1').style.background= 'url(/img/bookmark1.png) no-repeat';
    document.getElementById('b1_2').style.background= 'url(/img/bookmark2.png) repeat-x';
    document.getElementById('b1_3').style.background= 'url(/img/bookmark3.png) no-repeat';
    document.getElementById('b2_1').style.background= 'url(/img/bookmark_close1.png) no-repeat';
    document.getElementById('b2_2').style.background= 'url(/img/bookmark_close2.png) repeat-x';
    document.getElementById('b2_3').style.background= 'url(/img/bookmark_close3.png) no-repeat';
  }
  else
  {
    document.getElementById('t1').style.display = 'none';
    document.getElementById('a1').style.color= '#000000';
    document.getElementById('b1_1').style.background= 'url(/img/bookmark_close1.png) no-repeat';
    document.getElementById('b1_2').style.background= 'url(/img/bookmark_close2.png) repeat-x';
    document.getElementById('b1_3').style.background= 'url(/img/bookmark_close3.png) no-repeat';

  }
}

function t2_show(){
  if (document.getElementById('t2').style.display == 'none')
  {
    document.getElementById('t2').style.display = 'block';
    document.getElementById('t1').style.display = 'none';
    document.getElementById('a2').style.color= '#1a4aa3';
    document.getElementById('a1').style.color= '#000000';
    document.getElementById('b2_1').style.background= 'url(/img/bookmark1.png) no-repeat';
    document.getElementById('b2_2').style.background= 'url(/img/bookmark2.png) repeat-x';
    document.getElementById('b2_3').style.background= 'url(/img/bookmark3.png) no-repeat';
    document.getElementById('b1_1').style.background= 'url(/img/bookmark_close1.png) no-repeat';
    document.getElementById('b1_2').style.background= 'url(/img/bookmark_close2.png) repeat-x';
    document.getElementById('b1_3').style.background= 'url(/img/bookmark_close3.png) no-repeat';

  }
  else
  {
    document.getElementById('t2').style.display = 'none';
    document.getElementById('a2').style.color= '#000000';
    document.getElementById('b2_1').style.background= 'url(/img/bookmark_close1.png) no-repeat';
    document.getElementById('b2_2').style.background= 'url(/img/bookmark_close2.png) repeat-x';
    document.getElementById('b2_3').style.background= 'url(/img/bookmark_close3.png) no-repeat';
  }
}