var step = 1;
var delay = 10;
var height = 0;
var Hoffset = 0;
var Woffset = 0;
var yon = 0;
var xon = 0;
var pause = true;
var interval;
var name = navigator.appName;
var xPos = 50;
var yPos = 50;

function changePos() 
{
    height = $('body').innerHeight();
    width = $('body').innerWidth();
    Hoffset = $(window).scrollTop();
    Woffset = $(window).scrollLeft();
    $('#img').css('top', yPos + $(window).scrollTop());
    $('#img').css('left', xPos + $(window).scrollLeft());

    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() 
{
    $('#img').show();
    interval = setInterval('changePos()',delay);
}
function pauseResume() 
{
    if(pause) 
    {
        clearInterval(interval);
        pause = false;
    }
    else 
    {
        interval = setInterval('changePos()',delay);
        pause = true;
   }
}
start();
//  End -->