function switch1() 
{
var option=['div11','div12'];
for(var i=0; i<option.length; i++) 
{ obj=document.getElementById(option[i]);
obj.className=(obj.className=="visible")? "hidden" : "visible"; }
}
function switch2() 
{
var option=['div21','div22'];
for(var i=0; i<option.length; i++) 
{ obj=document.getElementById(option[i]);
obj.className=(obj.className=="visible")? "hidden" : "visible"; }
}
function switch3() 
{
var option=['div31','div32'];
for(var i=0; i<option.length; i++) 
{ obj=document.getElementById(option[i]);
obj.className=(obj.className=="visible")? "hidden" : "visible"; }
}
function switch4() 
{
var option=['div41','div42'];
for(var i=0; i<option.length; i++) 
{ obj=document.getElementById(option[i]);
obj.className=(obj.className=="visible")? "hidden" : "visible"; }
}
function switch5() 
{
var option=['div51','div52'];
for(var i=0; i<option.length; i++) 
{ obj=document.getElementById(option[i]);
obj.className=(obj.className=="visible")? "hidden" : "visible"; }
}
function switch6() 
{
var option=['div61','div62'];
for(var i=0; i<option.length; i++) 
{ obj=document.getElementById(option[i]);
obj.className=(obj.className=="visible")? "hidden" : "visible"; }
}
function switch7() 
{
var option=['div71','div71'];
for(var i=0; i<option.length; i++) 
{ obj=document.getElementById(option[i]);
obj.className=(obj.className=="visible")? "hidden" : "visible"; }
}