Hi, Im having difficulty coming up with a fixed point function

I'm trying to write a fixed point function, but its not working please let me know what modifications i should make to this. function [root,y,ea,iter]=fixedpoint(func,x0,es,maxiter) iter=0; ea=100; g(x0)+x= func(x0); while (1) x0= root; root=g(root); iter = iter + 1; if xr ~= 0, ea = abs((root - x0)/root) * 100; end if ea <= es | iter >= maxiter, break, end end y=func(root); end