function?getByClass(clsName,parent){
????//有傳入parent嗎？有的話就通過document.getElementById()獲取，沒有就通過document
????var?oParent?=?parent?document.getElementById(parent):document,
????????//取出來的值是一個數(shù)組
????????eles=[],
????????//把父元素下的元素取出來，遍歷一遍，找到一樣的class加到eles內(nèi)
????????elements?=?oParent.getElementsByTagName('*');

????for(var?i?=0,l=elements.length;i<l;i++){
????????if(elements[i].className==clsName){
????????????eles.push(elements[i]);
????????}
????}
????????return?eles;
}

/*
1.在標(biāo)題區(qū)域按下
2.要頁面中移動
3.釋放鼠標(biāo)時停止移動
*/

window.onload=drag；

function?drag{
????var?oTitle?=?getByClass('login_logo_webqq','loginPanel')[0];
????oTitle.onmousedown?=?fnDown;

}

function?fnDown(){
????document.onmousemove?=?function(event){
????????event?=?event||?window.event;
????????document.title?=?event.clientX?+?','?+event.clientY;

????}
????????
}