Open IFRAME page in new Window using JavaScript

Hi nmg,

I have checked your code,It is working fine,just add return false at the end of javascript function. 

HTML

Default.aspx

<div>
    <script type="text/javascript">
        function getIframeText() {
            var iframe0 = document.getElementById("iframe1");
            var iframe0document = iframe0.contentDocument.parentWindow || iframe0.contentWindow.document;
            var sourse = document.getElementById("iframe1").contentWindow.document.documentElement.outerHTML;
            var x = iframe0.src;
            window.open(x, 'mywindow', 'width=400,height=200,left=0,top=100,screenX=0,screenY=100')
            return false;
        }
    </script>
    <asp:Button ID="btnsend" runat="server" Text="show" OnClientClick="return getIframeText()" />
    <div>
        <table>
            <tr>
                <td style="width: 900px;">
                    Welcome to new topic
                    <div id="divsample" runat="server">
                    </div>
                </td>
                <td>
                    <div id="divparent" runat="server">
                        <iframe id="iframe1" src="mypage.htm" runat="server" height="400px"></iframe>
                    </div>
                </td>
            </tr>
        </table>
    </div>
</div>

mypage.html

<h1>
    My Page
</h1>

Screenshot