Vba function

Hello,
I need a VBA funcion that does the following:

function teta(Q, d, i, Ks)
n1 = 0.05
Q1 = Ks * (1/8)(n1-sin(n1))*(d^2)*(1/4)(1-(sin(n1)/n1))*d*i^(1/2)*(1000/60)

If Q1<Q
  n2 = n1 +0.05
  Q2 = Ks * (1/8)(n2-sin(n2))*(d^2)*(1/4)(1-(sin(n2)/n2))*d*i^(1/2)*(1000/60)
endif

If Q3<Q
  n2 = n2 +0.05
  Q3 = Ks * (1/8)(n3-sin(n3))*(d^2)*(1/4)(1-(sin(n3)/n3))*d*i^(1/2)*(1000/60)
Endif

.....
If Qn-1<Q
  nn = nn-1 +0.05
  Q3 = Ks * (1/8)(nn-sin(nn))*(d^2)*(1/4)(1-(sin(nn)/nn))*d*i^(1/2)*(1000/60)
Endif 

If Qn>=Q
 Else
  teta = nn
ENDIF
END Funtion

Thanks for the help.