  We solved the radial Schr"odinger equation analytically using the Exact
Quantization Rule approach to obtain the energy eigenvalues with the Extended
Cornell potential ECP. The present results are applied for calculating the mass
spectra of heavy mesons such as charmonium cc and bottomonium bb, and
heavylight mesons such as bottom-charm bc and charm-Strange cs for different
quantum states. Two special cases were considered when some of the potential
parameters were set to zero, resulting into Coulomb potential, and Cornell
potential, respectively. The present potential provides excellent results in
comparison with experimental data with a maximum error of 0.0065 GeV and work
of other researchers.
