screen size problem Kubuntu

[Avinash Sridhar]

hi,
Ive installed the latest Kubuntu hoary. have a Dell Inspiron 1100
Laptop. My screen size is only 640x480 . The laptop can support
1024x768 and this was detected at the install startup but somehow i am
not able to change the resoultion to the 1024x768. Through the
settings button on the taskbar the only option for display i get is
640x480. Where can i change this to get it to work .
Thanks in advance