怎么在父窗口判断子窗口有没有值？好兄弟谁解决了我给100分，在线等，急死了
operation.asp

怎么样在operation.asp 中写脚本判断 IFRAME中upfile6.asp里的影象上传东西了？及在线等，好兄弟谁解决了我给100分，在线等，急死了！！！

<script language= "JavaScript " type= "text/JavaScript ">

function Check()
{
if(blform.Casename.value== " ")
{
alert( "请填写手术名称！ ");
blform.Casename.focus();
return false;
}
if(document.frames( "mqs6 ").Accessories6.value== " ")//这里不行啊！！！！
{
alert( "请上传影象！ ");
return false;
}
//-->
</script>

<form action= "save_bl_action.asp " method= "post " name= "blform " id= "blform ">
<tr bgcolor= "#ffffff ">
<td align= "right "> <font color= "#FF0000 "> * </font> 病例名称： </td>
<td colspan= "5 " align= "left " bgcolor= "#ffffff "> <input name= "Casename " type= "text " id= "Casename " size= "55 " /> </td>
</tr>
<tr bgcolor= "#ffffff ">
<td align= "right "> 手术影像： </td>
<td colspan= "5 " align= "left "> <IFRAME name=mqs6 marginWidth=0 marginHeight=0 src=upfile6.asp?filename= <%=filename%> frameBorder=0 width=400 scrolling=no height=100> </IFRAME> </td>
</tr>
</form>

upfile6.asp

<!--#include FILE= "inc_upfile.asp "-->
<%on error resume next%>
<meta http-equiv= "Content-Type " content= "text/html;charset=gb2312 ">
<link href= "/img/index.css " rel= "stylesheet " type= "text/css ">
<script language= "JavaScript " src= "../inc/header.js "> </script>
<%
dim act
act = request( "act ")

sub err_msg(message)%>
<script> alert( ' <%=message%> ');history.go(-1); </script>
<script> window.close(); </script>