function secBoard(n)

{

for(i=0;i<secTable.cells.length;i++)

secTable.cells[i].className="sec1";

secTable.cells[n].className="sec2";

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

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

mainTable.tBodies[n].style.display="block";

}