  For the measurement of $N_s$ signals in $N$ events rigorous confidence bounds
on the true signal probability $p_{\rm exact}$ were established in a classical
paper by Clopper and Pearson [Biometrica 26, 404 (1934)]. Here, their bounds
are generalized to the HEP situation where cuts on the data tag signals with
probability $P_s$ and background data with likelihood $P_b<P_s$. The Fortran
program which, on input of $P_s$, $P_b$, the number of tagged data $N^Y$ and
the total number of data $N$, returns the requested confidence bounds as well
as bounds on the entire cumulative signal distribution function, is available
on the web. In particular, the method is of interest in connection with the
statistical analysis part of the ongoing Higgs search at the LEP experiments.
