.可以通过window.returnValue向打开对话框的窗口返回信息，当然也可以是对象。例如：
------------------------------
parent.htm
<script>
str =window.showModalDialog("modal.htm",,"dialogWidth=200px;dialogHeight=100px");
alert(str);
</script>
modal.htm
<script>
window.returnValue="http://www.51js.com";
</script>

var psAddStr="ProcessID="+ProcessID+"&AddFlag="+isAddFlag+"&BZBH="+vsBZBH+"&BZMC="+vsBZMC+"&BZFH="+vsBZFH+"&JD="+vsJD;
 
 var Result=window.showModalDialog("addSave.asp?"+psAddStr,'',"dialogHeight:250px;dialogWidth:250px;status:no;");