Here is an example (that does not need jQuery to work) :
var rotate = false;
function setbackground(){
window.setTimeout( "setbackground()", 5000);
newImage = rotate ? 'url(pict1.jpg)' : 'url(pict2.jpg)';
rotate = !rotate;
document.getElementById('change').style.backgroundImage = newImage;
}
与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…