  We review certain results for amplitudes of spectral flowed operators in
string theory on AdS_3. We present the modified Knizhnik-Zamolodchikov and null
vector equations to be satisfied by correlators including w=1 operators. We
then discuss the three point function of two w=1 and one w=0 operators in the
x-basis, and perform a consistency check on the definition of the w=1 operator.
We finally exhibit the steps in the calculation of the winding conserving four
point functions for operators in arbitrary spectral flowed sectors, both in the
m- and x-basis, under the only assumption that at least one of the operators is
in the spectral flowed image of the highest weight discrete representation.
