var current = 0;
var myPics = new Array();
function addPic(_p) {
myPics[myPics.length?myPics.length:0] = new Image();
myPics[myPics.length-1].src=_p; // preload all pics
}

addPic("images/green.jpg");
addPic("images/apple_snack.jpg");
addPic("images/apple_snack_2.jpg");
addPic("images/branch2.jpg");
addPic("images/appletree.jpg");
addPic("images/branch.jpg");
addPic("images/branch3.jpg");


function checkIt(val) {
current = Math.abs((current+parseInt(val))%myPics.length);
document.myimg.src = myPics[current].src;
}

document.write("<img name=myimg alt='' src='"+myPics[current].src+"'>");
var myTimer = setInterval('checkIt(1)',4000); // 4 second interval;