function?getByClass(clsname,parent){ var?oParent=parent?document.getElementById(parent):document;//找到光標按下的元素范圍 eles=[];//創建數組 elements=oParent.getElementsByTagName("*");//獲取所有符合條件的彈框節點 for(var?i=0,l=elements.length;i<l;i++) { ????????if(elements[i].className==clsname) { ????????eles.push(elements[i]);//增加符合條件的節點 } ????????} ????????return?eles;}window.onload=drag;//調用函數drag()???? ????????function?drag(){???? ????????var?oTitle=getByClass("login_logo_webqq","loginPanel")[0];//獲取符合條件的節點范圍???? ????????//拖曳???? ????????oTitle.onmousedown=fnDown();//調用函數fnDown()???? ????????//關閉???? ????????var?oClose=document.getElementById("ui_boxyClose");???? ????????oClose.onclick=function(){???? ????????document.getElementById("loginPanel").style.display="none";???? ????????}??? ????????}???? ????????function?fnDown(event){???? ????????event?=?event?||?window.event;???? ????????var?oDrag=document.getElementById('loginPanel'),//獲取彈框???? ????????//鼠標按下時光標與面板之間的距離???? ????????disX=event.clientX-oDrag.offsetLeft,???? ????????disY=event.clientY-oDrag.offsetTop;??? ???? ????????//移動???? ????????document.onmousemove=function(event){?? ????????event?=?event?||?window.event;?? ????????fnMove(event,disX,disY);??????}???????? ????????//釋放鼠標???????? ????????document.onmouseup=function()????????{ ????????document.onmousemove=null;???????? ????????document.onmouseup=null;????????}???? ????????}???? ????????function?fnMove(e,posX,posY){???? ????????var?oDrag=document.getElementById('loginPanel');//獲取彈框???? ????????l=e.clientX-posX;???? ????????t=e.clientY-posY;???? ????????WinW=document.documentElement.clientWidth?||?document.body.clientWidth;???? ????????WinH=document.documentElement.clientHeight?||?document.body.clientHeight;???? ????????maxW=WinW-oDrag.offsetWidth;???? ????????maxH=WinH-oDrag.offsetHeight;???? ????????if(l<0){???? ????????l=0;???? ????????}else?if(l>maxW){???? ????????l=maxW;???? ????????}???? ????????if(t<0){???? ????????t=0;???? ????????}else?if(t>maxH){???? ????????t=maxH;???? ????????}???? ????????oDrag.style.left=l+'px';???? ????????oDrag.style.top=t+'px';??? ???? ????????}