[BioC] annotating the results with association gene symbol

[Rabia [guest]]

HI,
I am new to R.I am using a windows base system.
I am following the tut by Daniel Swan.
After writing the following command
> gene.symbols <- getSYMBOL(probeset.list$ID, "hgu133plus2")

 get this eror:
Error in unlist(lookUp(x, data, "SYMBOL")) : 
  error in evaluating the argument 'x' in selecting a method for function 'unlist': Error in lookUp(x, data, "SYMBOL") : No keys provided command

Can any one help.
rabia

 -- output of sessionInfo(): 

> gene.symbols <- getSYMBOL(probeset.list$ID, "hgu133plus2")
Error in unlist(lookUp(x, data, "SYMBOL")) : 
  error in evaluating the argument 'x' in selecting a method for function 'unlist': Error in lookUp(x, data, "SYMBOL") : No keys provided

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