function copyText(obj)
{
    obj.select(); 
    copyToClipboard(obj.value);
}

function copyToClipboard(txt) {  
    if(window.clipboardData)  
    {  
        window.clipboardData.clearData();  
        window.clipboardData.setData("Text", txt);  
    }  
    else if(navigator.userAgent.indexOf("Opera") != -1)  
    {  
        window.location = txt;  
    }  
    else if (window.netscape)  
    {  
        try {  
            netscape.security.PrivilegeManager.enablePrivilege("UniversalXPConnect");  
        }  
        catch (e)  
        {  
            alert("您的瀏覽器不支援複製功能 請點選要複製的文字框 然後按ctrl+c 即可複製");  
        }  
        var clip = Components.classes['@mozilla.org/widget/clipboard;1'].createInstance(Components.interfaces.nsIClipboard);  
        if (!clip)  
            return;  
        var trans = Components.classes['@mozilla.org/widget/transferable;1'].createInstance(Components.interfaces.nsITransferable);  
        if (!trans)  
            return;  
        trans.addDataFlavor('text/unicode');  
        var str = new Object();  
        var len = new Object();  
        var str = Components.classes["@mozilla.org/supports-string;1"].createInstance(Components.interfaces.nsISupportsString);  
        var copytext = txt;  
        str.data = copytext;  
        trans.setTransferData("text/unicode",str,copytext.length*2);  
        var clipid = Components.interfaces.nsIClipboard;  
        if (!clip)  
            return false;  
        clip.setData(trans,null,clipid.kGlobalClipboard);  
    }  
    return true;  
}