[pvrusb2] Permission denied writing to cur_val

[Larry on the Dell]

Thank you all. The "sudo su" followed by entering 
the "sudo password" then
"echo s-video > cur_val" command does in fact
allow the cur_val to be changed as was suggested.

Thanks again,
Larry

Below is a brief synopsis for the benefit of other 
beginners like myself who may happen on to this:
---------------------------------------
Method to change pvrusb2 input (television, 
composite or s-video) by writing to "cur_val"
Ref: 
http://www.mythtv.org/wiki/index.php/Hauppauge_WinTV-PVR-USB2

(obtain root write permissions and authority by 
supplying sudo password for this mythbuntu system)
$ sudo su
[sudo] password for lj:

(change to the directory where "cur_val" is 
located,  note: system specific, yours may be 
different)
  cd 
/sys/devices/pci0000:00/0000:00:1a.7/usb6/6-1/pvrusb2/sn-8504958/ctl_input


(list directory containing "cur_val")
root at mythtv:/sys/devices/pci0000:00/0000:00:1a.7/usb6/6-1/pvrusb2/sn-8504958/ctl_input#ls
-al
total 0
drwxr-xr-x  2 root root    0 2008-10-21 12:35 .
drwxr-xr-x 56 root root    0 2008-10-21 12:33 ..
-rw-rw-r--  1 root root 4096 2008-10-21 18:43 cur_val
-r--r--r--  1 root root 4096 2008-10-21 18:43 enum_val
-r--r--r--  1 root root 4096 2008-10-21 18:43 name
-r--r--r--  1 root root 4096 2008-10-21 18:43 type

(Check the current value, here it shows currently 
set to "television")
root at mythtv:/sys/devices/pci0000:00/0000:00:1a.7/usb6/6-1/pvrusb2/sn-8504958/ctl_input#
cat cur_val
television

(Change to the s-video input)
root at mythtv:/sys/devices/pci0000:00/0000:00:1a.7/usb6/6-1/pvrusb2/sn-8504958/ctl_input#
echo s-video > cur_val

(Verify the change,  now shows the encoder input 
is set to input from the "s-video" connector)
#root at mythtv:/sys/devices/pci0000:00/0000:00:1a.7/usb6/6-1/pvrusb2/sn-8504958/ctl_input#
cat cur_val
s-video