I need to update a ListBox of a Form2 created dinamically. Let's say that in the event where I have to update this ListBox (in Form1 of course) I don't have a reference of this Form2 so I can't call the UpdateList method (and no, I can't make it static). I don't even know if there is a Form2 opened, it could be or not. What do you suggest? Is there a way to loop through all the open istances of Form2?

Code Sample:

//Form1

public void event()
{
    //UPDATE FORM2 LISTBOX
}

//SOMEWHERE IN FORM1

Form2 runTime = new Form2();

//Form2

public void UpdateList()
{
    //UPDATE LISTBOX
}