You could use something other than an array. Depending on what you are trying to accomplish you may want to use an ArrayList. It has a Contains Boolean function that will let you know if an item is in the array. You might also look at the HashTable. It stores items in a Key - Value pair. Great for doing direct retrievals when you know the key.

Try something like the following: Private Sub Button1_Click_1(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click Dim objRegEx As New System.Text.RegularExpressions.Regex("^[\w-\.]+@([\w-]+\.)+[\w-]{2,4}$") If objRegEx.IsMatch(TextBox1.Text) Then ErrorProvider1.SetError(sender, "") Else ErrorProvider1.SetError(sender, "Email address is not valid") End If End Sub You may have to adjust the regex depending on what you consider a valid email address.

How are you deploying your application to the other system? If you are just moving the EXE you are probably missing the Crystal dependency files. Create a Setup project for your app, it will grab all of the needed files and install them on the other system.

By what you've posted I cant see anything that would be causing a problem. When I get errors like this I always look at the SQL command that is being executed. (Either by examining the Update command in the Adapter or by doing a trace on SQL and seeing what exactly is being executed. Try looking at that, and if you don't see anything wrong with the SQL, post it here and I'll check it out. Good luck.

All you need to do is set the SelectedIndex of the ComboBox = -1. That will take care of it.