var i = 0;
imageObj = new Image();
images = new Array(); 

images[0]="img/start-u.png";
images[1]="img/referenzen-u.png";
images[2]="img/kontakt-u.png";
images[3]="img/impressum-u.png";

for(i=0; i<=4; i++)
{
	imageObj.src=images[i];
}