var brzina=1
function upalimigalo(){
migalo=document.getElementById("naokrug")
migalo.style.top=199
visina=migalo.offsetHeight
setTimeout('lefttime=setInterval("vrtimigalo()",17)', 0)
migalovisina=document.getElementById("vrtilo").offsetHeight
}
function vrtimigalo(){
if (parseInt(migalo.style.top)>(visina*(-1)+50))
migalo.style.top=parseInt(migalo.style.top)-brzina+"px"
else
migalo.style.top=parseInt(migalovisina)+50+"px"
}
window.onload=upalimigalo