Not enough input arguements error

Hi I am a beginner in MATLAB and having a problem. Here is my function

function [] = FingerprintFn(src_dir,path)
files=dir(path);
n=length(files);
nn=randi(n);
[filename, type]=strtok(files(nn).name,'.');
    I=imread([src_dir,files(nn).name]);
    imshow(I);
end

The files and src_dir are already defined and are present in workspace.

files = 'C:\Users\abc\123.bmp';
%and
src_dir = 'C:\Users\abc\';

The MATLAB displays the error in line that Not enough input arguements.

Please help :( :(