function hidead()

{document.getElementById("img1").style.display="none";}

var xPos = 300;

var yPos = 200; 

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;

img1.style.top = yPos;

function changePos() 

{

	width = document.body.clientWidth;

	height = document.body.clientHeight;

	Hoffset = img1.offsetHeight;

	Woffset = img1.offsetWidth;

	img1.style.left = xPos + document.body.scrollLeft;

	img1.style.top = yPos + document.body.scrollTop;

	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()

	 {

	 	img1.visibility = "visible";

		interval = setInterval('changePos()', delay);

	}

	function pause_resume() 

	{

		if(pause) 

		{

			clearInterval(interval);

			pause = false;}

		else 

		{

			interval = setInterval('changePos()',delay);

			pause = true; 

			}

		}

	start();