Initializing Axes title and Xlim - GUI

I have the program below, How can I set the Xlabel and Xlim before the push button is executed (initializing). I want to see the xlabel when the program is run and it should no be modified by any callbacks. The program below does this but I have to repeat the X-label several times:

   if true
    % code
function mygui3
%creating figure
f = figure('visible','on','Position',[350,100,650,400],'color', [0.25,0.83,0.83]);
t1_axes = axes('units','pixels','Position',[100,250,400,75]);
        title('first graph');
        xlabel('time');
        ylabel('data');
t2_axes = axes('units','pixels','Position',[100,50,400,75]);
%creating uicontrol
 i_button1 = uicontrol('Style','pushbutton',...
                     'string','err',...
                     'Position',[550,100,50,20],...
                     'callback',{@b1_callback});
 end
if true
i_button2 = uicontrol('style', 'pushbutton',...
                         'Position',[550,150,50,20],...
                         'backgroundcolor',[0.35,0.76,0.25],...
                         'callback',{@b2_callback});
i_button3 = uicontrol('style','pushbutton',...
                       'string','clear all',...
                       'Position',[550,200,50,20],...
                       'callback',{@b3_callback});
%initialized the GUI
set(i_button1,'string','sin(x)');
set(i_button2,'string','sin(x2)');
%programing uicontrol
    function b1_callback(hObject,eventdata)
        axes(t1_axes);
        x = 0:0.01:2*pi;
        plot(x,sin(x));
        title('first graph');
        xlabel('time');
        ylabel('data');
        set(t1_axes, 'XLim',[0 2*pi]);
        set(t1_axes, 'YLim',[-1 1]);
    end
    function b2_callback(hObject,eventdata)
        axes(t2_axes);
        x=0:0.01:2*pi;
        plot(x,sin(2*x));
        title('first graph');
        xlabel('time');
        ylabel('data');
        set(gca, 'XLim',[0 2*pi]);
        set(gca, 'YLim',[-1 1]);
    end
    function b3_callback(hObject,eventdata)
    cla(t1_axes,'reset');
    cla(t2_axes,'reset');
    end
 end

end