function[e] = onClickPlotAxes(varargin)

e = varargin{1};
obj = varargin{2};
handle = varargin{3};

location = get(obj, 'CurrentPoint');

previous_location = get(obj, 'UserData');


subj_pop = findobj('Tag','subj_pop');
sess_pop = findobj('Tag','sess_pop');

tmpsubj=get(subj_pop, 'Value');
if (iscell(tmpsubj)), selsubj = tmpsubj{1}; else    selsubj = tmpsubj;end;
tmpsess=get(subj_pop, 'Value');
if (iscell(tmpsubj)), selsess = tmpsess{1}; else    selsess = tmpsess;end;
if isempty(selsess) selsess = 1; end; if isempty(selsubj) selsubj = 1; end;
e.subjects(selsubj).sessions(selsess).sampling_rate

sampling_rate = e.subjects(selsubj).sessions(selsess).sampling_rate;

new_location.x = location(1,1);
new_location.y = location(1,2);
    
if isfield(previous_location, 'x');
       delta_t = abs(new_location.x -previous_location.x);       
       units = 'ms';
       if (delta_t > 1e3)
           units = 's';
           delta_t = delta_t/1e3;
       
       end
       display(sprintf('Delta time : %3.2f %s', delta_t, units));
        
end

previous_location = new_location;

set(obj, 'UserData', previous_location);