I needed a message function in a project that I could position and have time-out, and this little beast kind of grew from that...
It's become a bit of a Rube Goldberg Machine, having added several more features to it as I went, but it works well and I now use it in the project it was intend for, and probably will re-use it in future ones.
I know many others could implement something similar (or better and less complicated) themselves, but it just might be what you are looking for, and so I thought I'd offer it here for Christmas!
Just extract the contents of the attached zip to a folder and run the "MsgDlg Example.wbt" file to see it in action.
Merry Christmas.