chrome浏览器无法得到window.showModalDialog返回值解决方法


chrome浏览器functionobject
父页面：
function openwindows(){  
        var obj = new Object();  
        //obj.ordernumlst=new Array("001","002","003");  
        var retval = window.showModalDialog("ordervideo.jsp?orderIds="+"0010,0020,0030",obj,"dialogWidth=500px;dialogHeight=500px");  
          
        //for chrome  
        if(retval == undefined) {  
            retval = window.returnValue;  
        }  
        alert(retval);  
     }  
子页面：
function onload(){  
    var flag = '<%=request.getAttribute("resultflag")%>';  
    if(flag == 'error') {  
        //for chrome  
        if(window.opener != undefined) {  
            window.opener.returnValue = flag;  
        } else {  
            window.returnValue=flag;  
        }  
        window.close();  
    }  
    else if (flag == 'save') {  
        //for chrome  
        if(window.opener != undefined) {  
            window.opener.returnValue = flag;  
        } else {  
            window.returnValue=flag;  
        }  
        window.close();  
    }  
}