Nothing works from this code

(*Xq is a function of kz and ky*)
kztemp = Range[0.1, Pi, 0.1]; len = Length[kztemp]; kytemp = 
 Table[0, {len}]; For[h1 = 1, h1 <= len, 
 h1++, {Xqtemp = Xq /. {kz -> kztemp[[h1]]},
  temp = ky /. 
    Last[NMinimize[{Abs[Xqtemp], -Pi < ky < Pi}, ky, 
      MaxIterations -> 10000]],
  kytemp[[h1]] = temp}
 ];

NMinimize::nnum: The function value Abs[Xq] is not a number at {ky} = {-2.82734}. >> 
NMinimize::nnum: The function value Abs[Xq] is not a number at {ky} = {-2.82734}. >>
NMinimize::nnum: The function value Abs[Xq] is not a number at {ky} = {-2.82734}. >>
General::stop: Further output of NMinimize::nnum will be suppressed during this calculation. >>

what is Xq? It must be given in functional form to apply the rule kz-> kztemp[[h1]] ...