How to mount usb memory stick with write access for users

[embata_n1]

I install knoppix 4.02 on my HDD and i plug in my usbflash memory
then i go to konsole and write : mount /dev/sda1 /mnt/usbflash (where usbflash is previosly maked directory from me)
and i can read everything from my flash drive using GUI
but in GUI I logon with user account and I can't write on usbflash memory using GUI

can you help me

what do I have to do so I can write files on my flash using GUI

[Markus]

sudo mount /dev/sda1 /mnt/usbflash -o users,umask=000
or if already mounted: sudo mount /dev/sda1 /mnt/usbflash -o remount,rw,users,umask=000

Add the following line to /etc/fstab
/dev/sda1 /mnt/usbflash vfat noauto,users,exec,noatime,umask=000 0 0

btw, this forum section is for posting tips and/or tricks, not asking questions.

[coldfusio]

But you gave a good tip Markus. I tried alot like "mount -t vfat -o uid=500,gid=500 /dev/sda /mnt/sda" (or -o rw) or right clicking in the gui and changing rights there but got a "block device is not writable" I'm using Knoppix 3.7 and mtab gives
/dev/sda /mnt/sda vfat ro,nosuid,nodev,umask=000,uid=1000,gid=1000 0 0 after booting.

Edit: Write access is temporary, after each transaction ( ex deleting a file, deleting 100 files) it fails the next one.
Umounting and remounting makes it work again for 1 transaction.