  This note contains an attempt to relate Hecke's presentation of an ideal
class zeta function in a real quadratic field as an integral of the
nonholomorphic Eisenstein series along the loop on modular curve and Zagier's
decomposition of this zeta function into the sum of zeta functions of
indefinite quadratic forms. (See D.Zagier, A Kronecker limit formula for real
quadratic field.) It is a preliminary version.
