function disp(id)
{
var t1=document.getElementById("t1");
var t2=document.getElementById("t2");
if(id == "t1")
{
t1.style.display = "" ;
t2.style.display = "none";
}
else
if(id == "t2")
{
t1.style.display = "none" ;
t2.style.display = "";
}
return true ;
}