imgsrc=new Array();
imgsrc[1]="images/a_play.gif";
imgsrc[2]="images/p_play.gif";
imgsrc[3]="images/a_stop.gif";
imgsrc[4]="images/p_stop.gif";
img =new Array();
for (i=0; i< imgsrc.length; i++) {
  img[i]=new Image();
  img[i].src=imgsrc[i];
}
function change(cislo, obrazek) {
  {
    document[obrazek].src=img[cislo].src;
  }
}