Modal Popup in SharePoint 2010

Hello,
To create a modal popup in sharepoint 2010, follow these steps:

1. Create a visual webpart project.
2. In .ascx, wrtie the following code:
   <script type="text/javascript">

   function OpenDialog(URL) {

    var NewPopUp = SP.UI.$create_DialogOptions();

    NewPopUp.url = URL;

    NewPopUp.width = 900;

    NewPopUp.height = 500;

    SP.UI.ModalDialog.showModalDialog(NewPopUp);

  }

 </script>

 <asp:Button ID="btnOpenDialog" Text="Open Dialog"  
      OnClientClick="javascript:OpenDialog('/_layouts/settings.aspx'); return false;" runat="server" />

3. Deploy the webpart.

When you add the webpart on a page, and click on "Open Dialog" button, we will be noticing the page is opening in a modal popup window.