Javascript Set Timeout

window.setTimeout(fnRedirecTo,1000);
function fnRedirecTo()
{
if(document.getElementById("first").style.display=="none")
{
document.getElementById("first").style.display="block";
setTimeout(fnRedirecTo,1000);
}
else
{
document.getElementById("first").style.display="none";
setTimeout(fnRedirecTo,1000);
}
}