what is wrong with my SAS codes?

I have been trying to have SAS calculate tolerance and VIF by using the following codes:
proc logistic data=uis descending;
model DFREE = AGE BECK IVHX NDRUGTX / tol vif;
run;

and I was given the following error message. what is wrong with my codes? If I delete /tol vif, i can succcessfully have sas estimate the logistic regression model for me. Thanks!
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22
202
ERROR 22-322: Syntax error, expecting one of the following: ;, ABSFCONV, AGGREGATE, ALPHA,
BACKWARD, BEST, BINWIDTH, BUILDRULE, CL, CLODDS, CLPARM, CODING, CONVERGE, CORRB,
COVB, CT, CTABLE, DETAILS, DSCALE, EXPB, FAST, FCONV, FIRTH, GCONV, HIERARCHY,
INCLUDE, INFLUENCE, IPLOTS, ITPRINT, L, LACKFIT, LINK, MAXITER, MAXSTEP, NOCHECK,
NODUMMYPRINT, NOFIT, NOINT, NOLOGSCALE, OFFSET, OUTROC, PARMLABEL, PEVENT, PL,
PLCL, PLCONV, PLRL, PPROB, PSCALE, RIDGING, RISKLIMITS, ROCEPS, RSQUARE, SCALE,
SELECTION, SEQUENTIAL, SINGULAR, SLE, SLENTRY, SLS, SLSTAY, START, STB, STEPWISE,
STOP, STOPRES, TECHNIQUE, WALDCL, WALDRL, XCONV.
ERROR 202-322: The option or parameter is not recognized and will be ignored.
59 run;