var hh=0;
var inter;
 
//we show the box by setting the visibility of the element and incrementing the height smoothly
function ShowBox()
{
 
//Depending on the amount of text, set the maximum height here in pixels
     if(hh==1200)
     {
     clearInterval(inter);
     return;
     }
 
     obj = document.getElementById("coverlogin");
     obj.style.visibility = 'visible';
     hh+=5;
     obj.style.height = hh + 'px';
}
 
//same way as above but reversed
function HideBox()
{
     obj = document.getElementById("coverlogin");
 
     if(hh==5)
     {
     obj.style.visibility = 'hidden';
     obj.style.height = '0.1em';
     clearInterval(inter);
     return;
     }
     hh-=5;
     obj.style.height = hh + 'px';
}