I have mdiForm1 and Form1 as child
In Form1 I have a Menu mnuClear
Sure you can call this menu from mdiForm (button in PictureBox)
This procedure deletes the values ​​of local variables and they can not put in the module as Public Sub
Form1 is a document that can be opened with the command New. So I variables dimensioned in Form1 and not in a module as Public. If they were Public then they would be the same value in all open Form1 ...