Just add one line per file type:
AddArrayList("al1")
i=FileSearch(al1,AppPath&"\imgs","*.jpg")
j=FileSearch(al1,AppPath&"\imgs","*.pdf")
k=FileSearch(al1,AppPath&"\imgs","*.tif")
i = number of *.jpg files
j = number of *.pdf files
k = number of *.tif files
Best regards.