var xPos = 20;
var yPos = document.body.clientHeight || document.documentElement.clientHeight;
var step = 1;
var delay = 30; 
var height = 0;
var Hoffset = 0;
var Woffset = 0;
var yon = 0;
var xon = 0;
var pause = true;
var interval;
document.getElementById("imgFloat").style.top = yPos;


function changePos() {
width = document.body.clientWidth || document.documentElement.clientWidth;
height = 800; //document.body.clientHeight || document.documentElement.clientHeight;
Hoffset = document.getElementById("imgFloat").offsetHeight;
Woffset = document.getElementById("imgFloat").offsetWidth;
document.getElementById("imgFloat").style.left = (xPos + (document.body.scrollLeft || document.documentElement.scrollLeft)) + "px";
document.getElementById("imgFloat").style.top = (yPos + (document.body.scrollTop || document.documentElement.scrollTop)) + "px";
	if (yon) {
		yPos = yPos + step;
	}
	else {
		yPos = yPos - step;
	}

	if (yPos < 0) {
		yon = 1;
		yPos = 0;
	}

	if (yPos >= (height - Hoffset)) {
		yon = 0;
		yPos = (height - Hoffset);
	}

	if (xon) {
		xPos = xPos + step;
	}
	else {
		xPos = xPos - step;
	}

	if (xPos < 0) {
		xon = 1;
		xPos = 0;
	}

	if (xPos >= (width - Woffset)) {
		xon = 0;
		xPos = (width - Woffset);
	}
}

function start() {
document.getElementById("imgFloat").visibility = "visible";
interval = setInterval('changePos()', delay);
}


function pause_resume() {
if(pause) {
clearInterval(interval);
pause = false;
}
else {
interval = setInterval('changePos()',delay);
pause = true;
   }
}



start();