I'm trying to read in a file to do some calculations for a homework assignment and am encountering the following error message:   IDL> ps2 % READF: End of file encountered. Unit: 101          File: /rhome/palermo/ats652/hw2/SYNOPTIC.data % Execution halted at: PS2                48    /nas/rhome/palermo/ats652/hw2/ps2.pro   The section of code reads as follows:         READF, iunit, header                    ;get header line         FOR n = 1LL, nlines-2L DO BEGIN                 READF, iunit, u0, v0, pra0, t0, k0, i0, j0                 u[n-1LL] = u0                 v[n-1LL] = v0                 pra[n-1LL] = pra0                 T[n-1LL] = T0                 k[n-1LL] = k0                 i[n-1LL] = i0                 j[n-1LL] = j0         ENDFOR   The second READF is the one causing the problem.  I'm completely at a loss and running out of time.  Any suggestions you can offer would be greatly appreciated!