Thanks for replying Agni.
I don't know how to use .Net instead of using the Java script code, but I should probably look into that.
However, yesterday, we tried the ADService Webservice and it worked beautifully. We should have done that 3 days ago in stead of spending all the time trying to figure it out ourselves.
I still think future releases of Infopath, should have the logged on username as a function, similar to how the "Now()" function can be used.