function secBoard3(n)
{
for(i=0;i<secTable6.cells.length;i++)    //SCTABLEµÄÁÐÊý
secTable6.cells

[i].className="sec7";	 
secTable6.cells[n].className="sec7";	
if (n==6)secTable6.cells[n].className="sec7";	

for(i=0;i<mainTable6.tBodies.length;i++)
mainTable6.tBodies

[i].style.display="none";
mainTable6.tBodies

[n].style.display="block";
}