var FINAL_DELAY = 6; // seconds to leave on screen after image is finished moving
var FINAL_POS = 85; // where image should stop moving (in px from top of window)
var SPEED = 5; // speed factor for movement, higher = faster

var noPx = document.childNodes ? 'px' : 0; // determine if 'px' must be added when specifiying position

function rmove(itm) {
	itm.style.top = -4000 + noPx;
	itm.style.display = 'none';
}
function move(itm,maxpos) {
	pos = parseInt(itm.style.top);
	if ( pos < maxpos ) {
		newpos = (pos + SPEED) + noPx;
		itm.style.top = newpos;
		setTimeout('move(document.getElementById(\'interstit\'),' + maxpos + ')',2);
	} else {
		setTimeout('rmove(document.getElementById(\'interstit\'))',FINAL_DELAY*1000);
	}
}
window.onload = function () {
	if (document.getElementById) {
		document.getElementById('interstit').style.top = -500 + noPx;
		chk = document.getElementById('interstit').style.top + 'px';
		move(document.getElementById('interstit'),FINAL_POS);
	}
	initSwap(); // must be replaced to add rollover effects
}