float xdr_xtc_estimate_dt(FILE *fp, XDR *xdrs, int natoms, gmx_bool * bOK);
-int xdr_xtc_seek_time(real time, FILE *fp, XDR *xdrs, int natoms);
+ int xdr_xtc_seek_time(real time, FILE *fp, XDR *xdrs, int natoms,gmx_bool bSeekForwardOnly);
int xdr_xtc_seek_frame(int frame, FILE *fp, XDR *xdrs, int natoms);