function secBoard(n) 
{ 
for(i=0;i<secTable.cells.length;i++) 
secTable.cells[i].className="sec1"; 
secTable.cells[n+1].className="sec2"; 
for(i=0;i<mainTable.tBodies.length;i++) 
mainTable.tBodies[i].style.display="none"; 
mainTable.tBodies[n].style.display="block"; 
} 
//如果前面有一个可以用n+1

function secBoard1(n) 
{ 
for(i=0;i<secTable1.cells.length;i++) 
secTable1.cells[i].className="sec1"; 
secTable1.cells[n+1].className="sec2"; 
for(i=0;i<mainTable1.tBodies.length;i++) 
mainTable1.tBodies[i].style.display="none"; 
mainTable1.tBodies[n].style.display="block"; 
}