I just got the iphone 4g

i've been trying to get my own ringtones on my phone since i got it.

i went to mytinyphone.com and downloaded a .m4r music file, 30 seconds long and the instructions told me that all i need to do is download it to my computer and then double click the file and it will immeditaly be added to to ringtones section. well i double clicked it and it just opened up in itunes, it didnt save into the ringtones section. so then i deleted it, and dragged the file into the ringtones section and it wouldnt allow me to do that either.

i'm getting a little frusterated and i'm asking for any suggestions that may help.

all i want are ringtones to my phone!!

what am i doing wrong?