form modal

how can i prevent opening a form when it is already opened?
ie
if i press a cmdbutton, it opens a form.
how can i prevent that the same form is opened again when pressing the cmdbutton again?
i only want one instance of the form to be open

If you open the form Modally - then you wont even be able to press the command button

VB Code:

Dim oForm as New frmX
oForm.ShowDialog()

However, if you don't want the form to be displayed modally, then you could just set a module level variable whenever the form is opened.

If you do this though you would need a property in the new form (frmX) that holds the object reference of the parent form, and a property in the parent form that allows the module variable to be reset when the form is closed...

Have I made sense or just confused?

VB Code:

Dim oForm as New frmX
mbooFormShowing = True
oForm.ParentForm = Me 'ParentForm defined as a public property of frmX
oForm.Show

Then in frmX - when it closes/is disposed...

VB Code:

Me.ParentForm.FormShowing = False 'Property in the parent Form that updates mbooFormShowing