fsolve - "Not enough input arguments"

I've read all the relevant questions for fsolve and input arguments, and I believe I'm doing exactlyw aht the solutions recommend, but it won't work.

In a file saved to my MatLab path I have the function:

 function f = pb446(x)
 x1 = x(1);
 m1 = x(2);
 x4 = x(3);
 m4 = x(4);
 f(1) = x4 - .15*6000;
 f(2) = x1 * m1 - .66*6000;
 f(3) = (1-x1) * m1 + (1-x4) * m4 - 20;
 f(4) = m1 / m4 - 4.4;
 end

Then, in the command window:

 fsolve(pb446, [1 1 1 1])

It correctly references the pb446 function as far as I can tell, but returns:

 Not enough input arguments.
 Error in pb446 (line 2)
 x1 = x(1);

Even though I'm passing a vector of 4 values, it says there's not enough input. How can I make it accept the input?

Answer 1

[Walter Roberson]

   fsolve(@pb446, [1 1 1 1])

[Suman Dutta]

doesn't help!!

[Walter Roberson]

Please post your complete error message, everything in red.