a add / join wave files

join 2 or more wave files in to one wave file, all files must be the same (kHZ, Mono/Streo, Bits). also I use text to speech and text to wave. I was looking for somting like that I coun't find any code that works, so I took the graph from some other code and fnish it up for the join of the files. the text to speech was taken from microsot example files