Larry,

I ran the code through a converter and here are the results:

Class frmClients
   Private Shared m_instance As frmClients
   
   Shared Function Instance(parent As Form) As frmClients
      If m_instance Is Nothing Then
         m_instance = New frmClients(parent)
      End If
      Return m_instance
   End Function 'Instance
   
   Private Sub New(parent As Form)
      ...
   End Sub 'New
End Class 'frmClients '

Then elsewhere in your code to call the form

frmClient.Instance(this).Show

>Hi,
>im using VB.NET im not familiar in CS
>
>TIA
>
>>Larry,
>>
>>One approach is to use the Singleton design pattern. Here is a link to an article that describes this:
>>
>>http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dnbda/html/singletondespatt.asp
>>
>>Here is an example about how to limit your form to only one instance:
>>
>>1. Make the constructor of your form private.
>>2. Add a private static variable to your form, that is the type of your form.
>>3. Add a public static read-only property to your form that is the type of your form.
>>4. In the get method of this property, if the static variable is null, create a new instance of the form. Then return the static variable.
>>
>>Instead of a property, you can use a function.
>>
>>

>>class frmClients
>>{
>>#Region " Singleton Pattern "
>>    static frmClients m_instance;
>>    static frmClients Instance(Form parent)
>>    {
>>        if (m_instance == null)
>>            m_instance = new frmClients(parent);
>>        return m_instance;
>>    }
>>    private frmClients(Form parent)
>>    {
>>        ...
>>    }
>>#End Region
>>}
>>

>>
>>Then elsewhere in your code to call the form
>>

>>frmClient.Instance(this).Show;
>>

>>
>>IMPORTANT: Handle either the Closed or Closing event of frmClients by setting m_instance to null in Closed.
>>
>>
>>>Hi,
>>>
>>>I have mdi form and inside of the mdi form i have menu name "Form1" when i click the menu "Form1" the child form1 will popup as a child..but when i again the menu "Form1" the child form1 will popup again..
>>>
>>>how to control the form1 child to activate only once and detect if they are still activated...
>>>
>>>TIA
>>>
>>>Larry Santos