Creating Error Messages

I read another post on this site that provided a solution:

 Error MessageBox(%MsgStyle_OK, "", 0, 0, MsgGetText(30000, 1, "The message.") | Char(10) | Char(13) | MsgGetExplainText(30000, 1, "The description with bind variables %1, %2.", &FIRST, &SECOND)); 

This works, except that after the OK button is pressed another message box pops up with no title and just the number 0. If I can get rid of that second box this would be an acceptable solution. If I don't use Error then this box with a zero does not appear, but the message needs to be an error message (or at least stop processing).