[R] read.table missing values

[I.Szentirmai]

Dear R users,

I'm trying to read data from a tab-delimited text file to 
R, but I have problems with missing values. R gives this 
kind of error messages: "line 1 did not have 9 elements".

Could someone tell me how I can deal with missing values 
in this case?

Thanks a lot in advance,
Istvan