function board_change(num)
{
  for(i=1;i<4;i++)
  {
    if(i==num)
    {
      if(num==1)
      {
        document.getElementById('board_tab_div').innerHTML='<table border="0" cellspacing="0" cellpadding="0" class="hit_board_tab" align="left"><tr align="center"><td width="34" height="24" background="img/hit_board_tab.gif"><font color="#EC008C">國語</font></td><td width="34"><a href="javascript:void(0);" onclick="board_change(2);"><font color="#0066FF">西洋</font></a></td><td width="34"><a href="javascript:void(0);" onclick="board_change(3);"><font color="#0066FF">其它</font></a></td></tr></table>';
      }
      else if(num==2)
      {
        document.getElementById('board_tab_div').innerHTML='<table border="0" cellspacing="0" cellpadding="0" class="hit_board_tab" align="left"><tr align="center"><td width="34"><a href="javascript:void(0);" onclick="board_change(1);"><font color="#0066FF">國語</font></a></td><td width="34" height="24" background="img/hit_board_tab.gif"><font color="#EC008C">西洋</font></td><td width="34"><a href="javascript:void(0);" onclick="board_change(3);"><font color="#0066FF">其它</font></a></td></tr></table>';
      }
      else if(num==3)
      {
        document.getElementById('board_tab_div').innerHTML='<table border="0" cellspacing="0" cellpadding="0" class="hit_board_tab" align="left"><tr align="center"><td width="34"><a href="javascript:void(0);" onclick="board_change(1);"><font color="#0066FF">國語</font></a></td><td width="34"><a href="javascript:void(0);" onclick="board_change(2);"><font color="#0066FF">西洋</font></a></td><td width="34" height="24" background="img/hit_board_tab.gif"><font color="#EC008C">其它</font></td></tr></table>';
      }
      document.getElementById('board_main'+i).style.display='block';
    }
    else
    {
      document.getElementById('board_main'+i).style.display='none';
    }
  }
}
function title_change(img,content,more,num)
{
  if(num==1)
  {
    document.getElementById(img+'1').style.display="block";
    document.getElementById(img+'2').style.display="none";
    document.getElementById(content+'1').style.display='block';
    document.getElementById(content+'2').style.display='none'
    document.getElementById(more+'1').style.display='block';
    document.getElementById(more+'2').style.display='none'
  }
  else if(num==2)
  {
    document.getElementById(img+'2').style.display="block";
    document.getElementById(img+'1').style.display="none";
    document.getElementById(content+'2').style.display='block';
    document.getElementById(content+'1').style.display='none'
    document.getElementById(more+'2').style.display='block';
    document.getElementById(more+'1').style.display='none'
  }
}