不能弹出模式窗口

Question

HTML:
<script language="javascript" type="text/javascript">
function fnLaunch()
{window.showModalDialog("cesh3.aspx", myObject, "dialogHeight: 270px; dialogWidth: 520px; center: Yes; help: no; resizable: no; status: no;");}</script><asp:Button ID="Button1" runat="server" Text="Button" OnClientClick="fnLaunch();"  />当单击按钮时候为什么不能弹出模式窗口，B/S项目

Answer 1

function fnLaunch()
{ var a =window.showModalDialog("cesh3.aspx","", "dialogWidth:700px; dialogHeight:520px; status:no; scrollbars:no;Resizable=no");
}
myObject這個時啥？？

Answer 2

<script language="javascript" type="text/javascript">
function fnLaunch()
{window.showModalDialog("cesh3.aspx", 'myObject', "dialogHeight: 270px; dialogWidth: 520px; center: Yes; help: no; resizable: no; status: no;");}</script>

Answer 3

function fnLaunch()
{window.showModalDialog("cesh3.aspx", "", "dialogHeight: 270px; dialogWidth: 520px; center: Yes; help: no; resizable: no; status: no;");}

Answer 4

OnClientClick="fnLaunch();return false;" 
或OnClientClick="window.showModalDialog.. return false;"