window.onload = choosePic;

function choosePic() {
	var myPix = new Array("images/frame_corner2.png"," images/frame_corner3.png","images/frame_corner4.png","images/frame_corner5.png","images/frame_corner6.png");
	var randomNum = Math.floor((Math.random() * myPix.length));
	document.getElementById("myPicture").src = myPix[randomNum];
}