这个方法的内容该怎么写呢？

<html>
<body>
<script>
function showpic()
{
var arr = showModalDialog("1.htm", "", "dialogWidth:18.5em; dialogHeight:11.5em; status:0");if (arr != null){
  document.all.t.value=arr
}
}
</script>
<input id=t>
<a href="javascript:void(0)" onclick="showpic()">test</a>
</body>
</html>
1.htm
<script>
window.onunload=function(){
window.returnValue="hello"
}
</script>
<head>
function showpic()
{
var arr = showModalDialog("picture.html", "", "dialogWidth:18.5em; dialogHeight:11.5em; status:0");if (arr != null){
        document.all.t.value=arr
}
}
</head>
<body>
<input type=button onclick=“showpic()”>
</body>picture.html
<script>
window.onunload=function(){
window.returnValue="11111111"
}
</script>
大虾，
var arr = showModalDialog("picture.html", "", "dialogWidth:18.5em; dialogHeight:11.5em; status:0");arr 的值得不到阿。
另一贴中已经回了
picsite要为name,判断选中哪个