图片移动效果

function $get(id) { return document.getElementById(id); }

function addLoadEvent(func){
    var oldonload = window.onload;
    if (typeof window.onload != 'function') {
        window.onload = func;
    } else {
        window.onload = function(){
            oldonload();
            func();
        }
    }
}

function moveElement(elementID,final_x,final_y,interval) {
  if (!document.getElementById) return false;
  if (!document.getElementById(elementID)) return false;
  var elem = document.getElementById(elementID);
  if (elem.movement) {
    clearTimeout(elem.movement);
  }
  if (!elem.style.left) {
    elem.style.left = "0px";
  }
  if (!elem.style.top) {
    elem.style.top = "0px";
  }
  var xpos = parseInt(elem.style.left);
  var ypos = parseInt(elem.style.top);
  if (xpos == final_x && ypos == final_y) {
        return true;
  }
  if (xpos < final_x) {
    var dist = Math.ceil((final_x - xpos)/10);
    xpos = xpos + dist;
  }
  if (xpos > final_x) {
    var dist = Math.ceil((xpos - final_x)/10);
    xpos = xpos - dist;
  }
  if (ypos < final_y) {
    var dist = Math.ceil((final_y - ypos)/10);
    ypos = ypos + dist;
  }
  if (ypos > final_y) {
    var dist = Math.ceil((ypos - final_y)/10);
    ypos = ypos - dist;
  }
  elem.style.left = xpos + "px";
  elem.style.top = ypos + "px";
  var repeat = "moveElement('"+elementID+"',"+final_x+","+final_y+","+interval+")";
  elem.movement = setTimeout(repeat,interval);
}

function classNormal(iFocusBtnID,iFocusTxID){
    var iFocusBtns= $get(iFocusBtnID).getElementsByTagName('li');
    var iFocusTxs = $get(iFocusTxID).getElementsByTagName('li');
    for(var i=0; i<iFocusBtns.length; i++) {
        iFocusBtns[i].className='normal';
        iFocusTxs[i].className='normal';
    }
}

function classCurrent(iFocusBtnID,iFocusTxID,n){
    var iFocusBtns= $get(iFocusBtnID).getElementsByTagName('li');
    var iFocusTxs = $get(iFocusTxID).getElementsByTagName('li');
    iFocusBtns[n].className='current';
    iFocusTxs[n].className='current';
}

function iFocusChange() {
    if(!$get('ifocus')) return false;
    $get('ifocus').onmouseover = function(){atuokey = true};
    $get('ifocus').onmouseout = function(){atuokey = false};
    var iFocusBtns = $get('ifocus_btn').getElementsByTagName('li');
    var listLength = iFocusBtns.length;
    iFocusBtns[0].onmouseover = function() {
        moveElement('ifocus_piclist',0,0,5);
        classNormal('ifocus_btn','ifocus_tx');
        classCurrent('ifocus_btn','ifocus_tx',0);
    }
    if (listLength>=2) {
        iFocusBtns[1].onmouseover = function() {
            moveElement('ifocus_piclist',0,-200,5);
            classNormal('ifocus_btn','ifocus_tx');
            classCurrent('ifocus_btn','ifocus_tx',1);
        }
    }
    if (listLength>=3) {
        iFocusBtns[2].onmouseover = function() {
            moveElement('ifocus_piclist',0,-400,5);
            classNormal('ifocus_btn','ifocus_tx');
            classCurrent('ifocus_btn','ifocus_tx',2);
        }
    }
    if (listLength>=4) {
        iFocusBtns[3].onmouseover = function() {
            moveElement('ifocus_piclist',0,-600,5);
            classNormal('ifocus_btn','ifocus_tx');
            classCurrent('ifocus_btn','ifocus_tx',3);
        }
    }
}

setInterval('autoiFocus()',5000);
var atuokey = false;
function autoiFocus() {
    if(!$get('ifocus')) return false;
    if(atuokey) return false;
    var focusBtnList = $get('ifocus_btn').getElementsByTagName('li');
    var listLength = focusBtnList.length;
    for(var i=0; i<listLength; i++) {
        if (focusBtnList[i].className == 'current') var currentNum = i;
    }
    if (currentNum==0&&listLength!=1 ){
        moveElement('ifocus_piclist',0,-200,5);
        classNormal('ifocus_btn','ifocus_tx');
        classCurrent('ifocus_btn','ifocus_tx',1);
    }
    if (currentNum==1&&listLength!=2 ){
        moveElement('ifocus_piclist',0,-400,5);
        classNormal('ifocus_btn','ifocus_tx');
        classCurrent('ifocus_btn','ifocus_tx',2);
    }
    if (currentNum==2&&listLength!=3 ){
        moveElement('ifocus_piclist',0,-600,5);
        classNormal('ifocus_btn','ifocus_tx');
        classCurrent('ifocus_btn','ifocus_tx',3);
    }
    if (currentNum==3 ){
        moveElement('ifocus_piclist',0,0,5);
        classNormal('ifocus_btn','ifocus_tx');
        classCurrent('ifocus_btn','ifocus_tx',0);
    }
    if (currentNum==1&&listLength==2 ){
        moveElement('ifocus_piclist',0,0,5);
        classNormal('ifocus_btn','ifocus_tx');
        classCurrent('ifocus_btn','ifocus_tx',0);
    }
    if (currentNum==2&&listLength==3 ){
        moveElement('ifocus_piclist',0,0,5);
        classNormal('ifocus_btn','ifocus_tx');
        classCurrent('ifocus_btn','ifocus_tx',0);
    }
}
addLoadEvent(iFocusChange);

来源于：http://www.tgous.com/