Having problems in updating applications

[BornIdiot]

Hi,
I am using Ubuntu 9.04. Whenever I use the apt-get command to install new applications, it gives an error which says something like a lock not found.(like /var/.... lock not found).
Please help because it's started to irritate me.

Thank in advance.

[Partyboi2]

Hi, are you trying to use apt-get while having another package manager (Synaptic, Update Manager etc) open?