Repeating Progress Bar

I have a winform that calls to another winform (progressform) which comes up when an execute call of a function is made. What i am trying to do is have a progress bar inifinite loop untill the function returns its value and the progress window gets the command to close. The progress bar is not to have anything to do with the actual progress of the data being read its just to show that the application is "working" to get their data.

The function gets set to the datatable variable dt in this line
dt = myRunner.GetData(CurrentQuery.Text, QueryParameters)

I want the progess bar to continue until dt has been assigned a value or when the progressform.close() command is called