Please Help

[yoonus]

 This is a simple function in which I want to calculate the square root of
number ,which is u in this case. I got lot errors . please debug and help me
out.



This is the code
function x0 = mysolve(u)

 options.abstol=1e-5;
 f = @(x) x^2-u;

 x0 = fsolve('f', 1);

 return;

Errors

error: `f' undefined near line 1 column 37
error: evaluating assignment expression near line 1, column 35
error: called from `__fsolve_fcn__'
error: fsolve: evaluation of user-supplied function failed
error: evaluating assignment expression near line 6, column 5
error: called from `mysolve' in file `/octave_files/cafs/mysolve.m'


Thanks
Yoonus