When you start defining a function in scilab, scilab changes how it
spaces commands. Compare

-->x = 2;
 
-->x^2;
 
-->// last answer was 4
 
-->ans
 ans  =
 
    4.  
 
-->


With the function definition f(x) = x^2
-->function y = f(x)
-->y = x^2;
-->endfunction
 
-->f(2);
 
-->// last answer was 4
 
-->ans
 ans  =
 
    4.  
 
-->

Notice the single spacing while the function is being defined.

A common beginners error is to write `end function' instead of the
one word `endfunction'. Scilab still thinks you are definding
a function, it fact it thinks you are now starting a new function
inside the first function. You now have to type endfunction twice
to end the definition of the first function.

-->function y = f(x)
-->y = x^2;
-->end function
-->f(2); // note the spacing, I haven't ended the function
-->you stupid scilab why are you not giving 4
-->damn it give me back my old line
-->endfunction 
-->// we ended the second function on line 3
-->endfunction
end function
 !--error 34 
incorrect control intruction syntax
at line       3 of function f called by :  
endfunction
 
 
-->// now we are back and tells us about our error on line 3