var imgs = new Array( './content/images/zdjecia/1.jpg', './content/images/zdjecia/2a.jpg', './content/images/zdjecia/3a.jpg', './content/images/zdjecia/4a.jpg', './content/images/zdjecia/5a.jpg');
var pos = 0;

function chImg()
{
var i = document.getElementById( 'imgField' );

i.src = './' + imgs[ pos++ ];

if( pos >= 5 )
{
pos = 0;
}

window.setTimeout( 'chImg()', 4000 );
}