Javascript exception when opening window for the second time

Hello community.

I'm performing CRUD operations on a TelerikRadWindow, which works fine at the first time but when i try to do it a second time throws Javascript exception "Uncaught TypeError: Cannot read properties of null (reading 'show') at openRadWindow". Any ideas on what it could be? Thank you in advance!

// window code, which bounds a child user control containing the crud form


                 
                    
                        
                            
                                
                            
                        
                    
                   

//JS

function openRadWindow() {
            var radwindow = $find('<%=UserListDialog.ClientID %>');
           radwindow.show();
        }