如何只显示一个showModelessDialog页面

我现在做了一个加载时候就可以弹出showModelessDialog的父窗体页面，但是在此父窗体页面上又有一个button点击后还是要弹出这个showModelessDialog页面，这样就弹出了两个我怎么控制每一次点击只弹出一个呢？我想的是父窗体获取showModelessDialog页面的关闭事件然后在点击button弹出新的窗口以前先关闭原来的但是不知道可以不可以也不知怎么实现求帮助在线等ing

解决方案 »

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补充问题：我做了这个页面解释一下这个页面：
当页面加载完成后，同时加载了showModelessDialog页面，其textbox值为1。点击在父窗体上的button，要实现将showModelessDialog页面上的textbox值变为0。这个值就是通过showModelessDialog传过去的参数。要怎么做呢？我做了一个比较笨的方法，就是在点击button的时候又调用一遍加载showModelessDialog页面方法，可这样showModelessDialog页面就变成两个了，怎么控制只有一个呢？
源码奉上：
父窗体：
<body onload="initpage()">
    <input id="Button1" type="button" value="button"  onclick="ClkBtn()"/>
    <script type="text/javascript" language="javascript">
        function initpage() {
            onLoadSmallCmr(0);
        }
        function onLoadSmallCmr(cmrShow) {
                var iTop = (window.screen.availHeight - 450) / 2 + 22;
                var iLeft = (window.screen.availWidth - 300) / 2 - 52;
                window.showModelessDialog("SideStream.htm",  cmrShow, "dialogHeight=300px;dialogWidth=300px;top=" + iTop + ";left=" + iLeft + ";toolbar =no;menubar=no;scroll=no;resizable=yes;location=no;status=no");
        }        function ClkBtn() {
           onLoadSmallCmr(1);
        }
    </script>
</body>
子窗体：SideStream.htm
<body onload="recValue()">
    <input id="Text1" type="text" /><br />
    <input id="Button1" type="button" value="button" onclick="retValue()" />
    <script type="text/javascript" language="javascript">
        function recValue() {
            var recValue = window.dialogArguments;
            document.getElementById("Text1").value = recValue;
        }        function retValue() {
            window.close();
        }
    </script>
</body>
恩，是我理解错了
我在网上查了资料，真是不怎么全，都是ModalDialog的，ModelessDialog资料确实很少
本着送佛送到西的原则，研究了一下，写了完整的sample，你试试吧<HTML>
<HEAD>
<TITLE>showModelessDialogEX.htm</TITLE>
<SCRIPT>
var sUserName="";
var intval = null;
var m = null;
function fnCallDialog(){
if(m)
{
}else{
m = showModelessDialog("myDialog.html",window,"status:false;dialogWidth:300px;dialogHeight:300px");
}
if(!intval){
intval = setInterval(function(){
if(m && m.closed)
m = null;
}, 500);
}
}
function fnUpdate(){
    document.getElementById("oName").innerText = sUserName;
}
</SCRIPT></HEAD><BODY><P>Enter<SPAN STYLE="color:red;font-size:24" id="oName">JoyoShuai</SPAN></P><INPUT TYPE="button"VALUE="Display Modeless Dialog" onclick="fnCallDialog()"></BODY>
</HTML><HTML>
<HEAD>
<TITLE>myDialog.htm</TITLE>
<SCRIPT>
function fnGetInfo() {
var sData = dialogArguments;
sData.sUserName = document.getElementById("oEnterName").value;
sData.fnUpdate();
}
function fnCancel() {
var sData = dialogArguments;
sData.sUserName = "Joan";
sData.fnUpdate();
}
</SCRIPT>
</HEAD>
<BODY>
Enter your <SPAN STYLE="text-decoration:underline">F</SPAN>irst Name</LABEL>
<INPUT id="oEnterName"><INPUT VALUE="Apply" TYPE=button onclick="fnGetInfo();" >
<INPUT VALUE="Ok" TYPE=button onclick="fnGetInfo();window.close();" >
<INPUT VALUE="Cancel" TYPE=button onclick="window.close();">
</BODY>
</HTML>
妈的，被网上资料误导了，用 setInterval干嘛？改一下<HTML>
<HEAD>
<TITLE>showModelessDialogEX.htm</TITLE>
<SCRIPT>
var sUserName="";
var m = null;
function fnCallDialog(){
if(!m || m.closed)
{
m = showModelessDialog("myDialog.html",window,"status:false;dialogWidth:300px;dialogHeight:300px");
}
}
function fnUpdate(){
    document.getElementById("oName").innerText = sUserName;
}
</SCRIPT></HEAD><BODY><P>Enter<SPAN STYLE="color:red;font-size:24" id="oName">JoyoShuai</SPAN></P><INPUT TYPE="button"VALUE="Display Modeless Dialog" onclick="fnCallDialog()"></BODY>
</HTML><HTML>
<HEAD>
<TITLE>myDialog.htm</TITLE>
<SCRIPT>
function fnGetInfo() {
var sData = dialogArguments;
sData.sUserName = document.getElementById("oEnterName").value;
sData.fnUpdate();
}
function fnCancel() {
var sData = dialogArguments;
sData.sUserName = "Joan";
sData.fnUpdate();
}
</SCRIPT>
</HEAD>
<BODY>
Enter your <SPAN STYLE="text-decoration:underline">F</SPAN>irst Name</LABEL>
<INPUT id="oEnterName"><INPUT VALUE="Apply" TYPE=button onclick="fnGetInfo();" >
<INPUT VALUE="Ok" TYPE=button onclick="fnGetInfo();window.close();" >
<INPUT VALUE="Cancel" TYPE=button onclick="window.close();">
</BODY>
</HTML>
谢谢您这么细心的回答，但是您还是意错意了，我不是要触发子窗体的button传值给父窗体，我想要父窗体的button触发传值给子窗体肿么弄呢？
也就是说当子窗体没有关闭的时候，我的父窗体通过点击button刷新子窗体。
<HTML>
<HEAD>
<TITLE>showModelessDialogEX.htm</TITLE>
<SCRIPT>
var sUserName="";
var m = null;
function fnCallDialog(){
if(!m || m.closed)
{
m = showModelessDialog("myDialog.html",window,"status:false;dialogWidth:300px;dialogHeight:300px");
}
}
function fnUpdate(){
    document.getElementById("oName").innerText = sUserName;
}
</SCRIPT></HEAD><BODY><P>Enter<SPAN STYLE="color:red;font-size:24" id="oName">JoyoShuai</SPAN></P><INPUT TYPE="button"VALUE="Display Modeless Dialog" onclick="fnCallDialog()">
<INPUT TYPE="button"VALUE="Display Modeless Dialog" onclick="m.document.getElementById('linkA').click()"></BODY>
</HTML><HTML>
<HEAD>
<TITLE>myDialog.htm</TITLE>
<base target="_self"></base>
<SCRIPT>
function fnGetInfo() {
var sData = dialogArguments;
sData.sUserName = document.getElementById("oEnterName").value;
sData.fnUpdate();
}
function fnCancel() {
var sData = dialogArguments;
sData.sUserName = "Joan";
sData.fnUpdate();
}
</SCRIPT>
</HEAD>
<BODY>
Enter your <SPAN STYLE="text-decoration:underline">F</SPAN>irst Name</LABEL>
<INPUT id="oEnterName"><INPUT VALUE="Apply" TYPE=button onclick="fnGetInfo();" >
<INPUT VALUE="Ok" TYPE=button onclick="fnGetInfo();window.close();" >
<INPUT VALUE="Cancel" TYPE=button onclick="window.close();">
<a id="linkA" href="http://www.baidu.com" style="display:none">baidu</a>
</BODY>
</HTML>
触发子窗体的控件点击造成跳转，这是一个方法还有一个方法，如果子窗口是打开状态的话，先关闭它<HTML>
<HEAD>
<TITLE>showModelessDialogEX.htm</TITLE>
<SCRIPT>
var sUserName="";
var m = null;
function fnCallDialog(){
if(m && !m.closed)
m.close();
if(!m || m.closed)
{
m = showModelessDialog("myDialog.html",window,"status:false;dialogWidth:300px;dialogHeight:300px");
}
}
function fnUpdate(){
    document.getElementById("oName").innerText = sUserName;
}
</SCRIPT></HEAD><BODY><P>Enter<SPAN STYLE="color:red;font-size:24" id="oName">JoyoShuai</SPAN></P><INPUT TYPE="button"VALUE="Display Modeless Dialog" onclick="fnCallDialog()">
<INPUT TYPE="button"VALUE="redirect Dialog" onclick="m.document.getElementById('linkA').click()">
<INPUT TYPE="button"VALUE="Display Modeless Dialog Again" onclick="fnCallDialog()"></BODY>
</HTML><HTML>
<HEAD>
<TITLE>myDialog.htm</TITLE>
<base target="_self"></base>
<SCRIPT>
function fnGetInfo() {
var sData = dialogArguments;
sData.sUserName = document.getElementById("oEnterName").value;
sData.fnUpdate();
}
function fnCancel() {
var sData = dialogArguments;
sData.sUserName = "Joan";
sData.fnUpdate();
}
</SCRIPT>
</HEAD>
<BODY>
Enter your <SPAN STYLE="text-decoration:underline">F</SPAN>irst Name</LABEL>
<INPUT id="oEnterName"><INPUT VALUE="Apply" TYPE=button onclick="fnGetInfo();" >
<INPUT VALUE="Ok" TYPE=button onclick="fnGetInfo();window.close();" >
<INPUT VALUE="Cancel" TYPE=button onclick="window.close();">
<a id="linkA" href="http://www.baidu.com" style="display:none">baidu</a>
</BODY>
</HTML>
非常感谢 clark_kidd  的解答