imgLeftStart = 510;
imgLeftEnd = 600;
imgLeft = imgLeftStart;
imgTop = 20;
moveStep = 2;
moveSpeed = 80;
function moveImgX(){
	document.getElementById("img1").style.top = imgTop;
	document.getElementById("img1").style.left = imgLeft;
	if(imgLeftEnd-imgLeftStart > 0){
		imgLeft += moveStep;
		if(imgLeft > imgLeftEnd){
			imgLeft = imgLeftStart;
		}
	}else{
		imgLeft -= moveStep;
		if(imgLeft < imgLeftEnd){
			imgLeft = imgLeftStart;
		}
	}
	document.getElementById("img1").style.visibility="visible";
	setTimeout("moveImgX()",moveSpeed);
}