telerik window does not show

On page I write telerik window:

<telerik:RadWindow ID="Diction开发者_C百科aryWindow" runat="server"></telerik:RadWindow>

on this page I run javascript when user click on button:

<script type="text/javascript">
function getWindow() { return document.getElementById("<%= DictionaryWindow.ClientID %>"); }

var oWin = getWindow();
    if (oWin != null) {            
        oWin.setUrl("WebForm1.aspx");
        oWin.set_width(800);
        oWin.set_height(800);
        oWin.Show();
        oWin.Center();

    }
</script>

an error apears: Object doesn't support this property or method. I find this javascript on the net like example. Is this the correct way to get telerik window to show? Can I get the window to appear some another way?

I would use the RadWindowManager to access your windows:

function UseRadWindow()
{
   var oManager = GetRadWindowManager();
   var oWnd = oManager.GetWindowByName("DictionaryWindow");
   oWnd.setUrl("WebForm1.aspx");        
   oWnd.SetWidth(800);
   oWnd.SetHeight(800);
   oWnd.Show();
   oWnd.Center();
}

You could also do it by accessing the window directly:

function UseRadWindow()
{
   var oWnd = $find("<%= DictionaryWindow.ClientID %>"); 
   oWnd.setUrl("WebForm1.aspx");        
   oWnd.SetWidth(800);
   oWnd.SetHeight(800);
   oWnd.Show();
   oWnd.Center();
}

Take a look at their client-side API docs:

Telerik RadWindowManager Client-Side API

getElementById will return the element, while in order to get access to the control's client API, you need to get a reference to its object - that is why you need to use $find().

Javascript is a case-sensitive language. The telerik controls use (mostly) camel-casing for their javascript methods. According to the documentation, you probably want:

oWin.show();

oWin.center();