moveElement函数与positionMessage函数

function moveElement(elementID,final_x,final_y,interval){
    if (!document.getElementById) return false;
    if (!document.getElementById(elementID)) return false;
    var elem=document.getElementById(elementID);
    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) {xpos++;}
    if (xpos>final_x) {xpos--;}
    if (ypos<final_y) {ypos++;}
    if (ypos>final_y) {ypos--;}
    elem.style.left=xpos+"px";
    elem.style.top=ypos+"px";
    var repeat="moveElement(‘"+elementID+"‘,"+final_x+","+final_y+","+interval+")";
    movement=setTimeout(repeat,interval);
    
}
 
 addLoadEvent(moveMessage);

function positionMessage(){
    if (!document.getElementById) return false;
    if (!document.getElementById("message")) return false;
        var elem=document.getElementById("message");
        elem.style.position="absolute";
        elem.style.left="50px";
        elem.style.top="100px";
        moveElement("message",200,100,10);
    }
addLoadEvent(positionMessage);