function showdiv(x,y,strHtm,id,width,height){
var elm = document.getElementById(id);
if(!elm){
elm = document.createElement("div");
elm.id = id
document.body.appendChild(elm);
}
elm.style.position = 'absolute';
//elm.style.overflow='auto';
elm.innerHTML = strHtm;
elm.style.zIndex = 30;
elm.style.background = '#fff';
elm.style.width = width + 'px';
elm.style.height = height + 'px';
elm.style.left = x + 'px';
elm.style.top = y + 'px';
elm.style.display='';
}
//提前加在此div方法
var ex=(parseInt(document.body.clientWidth)-680)/2;
var ey=(parseInt(document.body.clientHeight)-350)/2;
showdiv(ex,ey,aStr,'modifytaskdiv',680,350);