Mac says i don't have permission to update software, please help!?!

[pleazehelp]

I am currently using Mac OS X version 10.7.2 and when i click software update it says i do not have permission to do it. I have tred going to dik utility and clicking on repair disk permission but it still wont let me! I am also the only administrater. Any ideas on have to sort this out would be much appreciated???

 

[judethat]

Look at security and check if you have a tick in the option to allow updates.