  We present an undated comprehensive analysis for the simplest dark matter
model in which a real singlet scalar with a $Z_2$ symmetry is introduced to
extend the standard model. According to the observed dark matter abundance, we
predict the dark matter direct and indirect detection cross sections for the
whole parameter space. The Breit-Wigner resonance effect has been considered to
calculate the thermally averaged annihilation cross section. It is found that
three regions can be excluded by the current direct and indirect dark matter
search experiments. In addition, we also discuss the implication of this model
for the Higgs searches at colliders.
