window.onload=init;
function init(){
   
if (document.images)
{
  pic1= new Image(200,300);
  pic1.src="images/img1_subtitle_m.jpg";

  pic2= new Image(200,300);
  pic2.src="images/img2_subtitle_m.jpg";

  pic3= new Image(200,300);
  pic3.src="images/img3_subtitle_m.jpg";

  pic4= new Image(200,300);
  pic4.src="images/img4_subtitle_m.jpg";
}


}
function link_1_on(){
    var img = document.getElementById('mi1');
    img.setAttribute("src", pic1.src );
}

function link_1_off(){
    var img = document.getElementById('mi1');
    img.setAttribute("src", "images/img1_subtitle.jpg");
}

function link_2_on(){
    var img = document.getElementById('mi2');
    img.setAttribute("src",pic2.src );
}

function link_2_off(){
    var img = document.getElementById('mi2');
    img.setAttribute("src", "images/img2_subtitle.jpg");
}

function link_3_on(){
    var img = document.getElementById('mi3');
    img.setAttribute("src",pic3.src );
}

function link_3_off(){
    var img = document.getElementById('mi3');
    img.setAttribute("src", "images/img3_subtitle.jpg");
}

function link_4_on(){
    var img = document.getElementById('mi4');
    img.setAttribute("src", pic4.src);
}

function link_4_off(){
    var img = document.getElementById('mi4');
    img.setAttribute("src", "images/img4_subtitle.jpg");
}