Visual Basic .NET

If I click a menu to open a form which already open...the vb.net opens a new window while existing open window is there...i want to restric the opening of a new instance of an already opened form... ...

Hello,        In my program I am doing a lot of connections to the database one after the other and retrieving lots of records from the database. However I am getting the message below when sometimes running this program. It would ...