Function call in verilog

I have written a verilog for ma project work. In it,I wrote the followin code:

for(i=n-2;i>=0;i=i-1)
begin
ge (w[2*i+1],w[2*i],w[2*i+2],w[2*i+3],a[i],b[i]);
end

I am getting error. how should i declare ' i ' ? First I declared as integer and then i tried genvar. Everytime it is showing error. Also it is showing block identifier is required. Pls help me out.