window.open如何让窗口在最上面

Question

function sendmessage()   
        {   
            var top = (window.screen.width)/2-400;   
            var left = (window.screen.height)/2;   
            window.open("sendmessage.jsp","","width=570,height=280,toolbar=0,location=0,directories=0,status=1,menubar=0,scrollbars=1,resizable=1,top="+top+",left="+left);   
        }  
我通过点击按钮然后执行上面的JS函数来打开新的窗口页面，但它不是在最上面的，我想让弹出的窗口在最上面，不关闭此窗口就不能进行其它的操作，怎么办？

Answer 1

function sendmessage()   
        {   
            var top = (window.screen.width)/2-400;   
            var left = (window.screen.height)/2;   
            var newW=window.open("sendmessage.jsp","","width=570,height=280,toolbar=0,location=0,directories=0,status=1,menubar=0,scrollbars=1,resizable=1,top="+top+",left="+left);
           newW.focus();
        }

Answer 2

k=showModalDialog('sendmessage.jsp','','dialogWidth:205px;status:no;dialogHeight:183px');
用这个吧，k就是从小窗口传回来的值