window.showModalDialog firefox上的显示有关问题 _HTML/CSS

window.showModalDialog firefox下的显示问题
var www=window.showModalDialog("url,"","dialogHeight: 640px; dialogWidth: 900px; edge: Raised; center: Yes; help: No; resizable: no; status: No;");

IE下显示正常，firefox下的显示居左

需要怎么改呢。

------解决方案--------------------

JScript code

var url='12-1特价古筝.htm'; //转向网页的地址;
var name=''; //网页名称，可为空;
var iWidth=430; //弹出窗口的宽度;
var iHeight=430; //弹出窗口的高度;
var iTop = (window.screen.availHeight-30-iHeight)/2; //获得窗口的垂直位置;
var iLeft = (window.screen.availWidth-10-iWidth)/2; //获得窗口的水平位置;
window.open(url,name,'height='+iHeight+',,innerHeight='+iHeight+',width='+iWidth+',innerWidth='+iWidth+',top='+iTop+',left='+iLeft+',toolbar=no,menubar=no,scrollbars=auto,resizeable=no,location=no,status=no');