function img_onOver (id) {
	var source = document.getElementById(id).src;
	var endung = source.search(/.gif/);
	if (endung != -1) {
    var newsource = source.replace(/.gif/g, "_over.gif");
		var newimage = new Image();
  } else {
    var newsource = source.replace(/.jpg/g, "_over.jpg");
		var newimage = new Image();
  }
	newimage.src = newsource;
	document.getElementById(id).src = newimage.src;
	// TextCheck
	VisibilitySwitchText(id);
}

function img_onOut (id) {

	var source = document.getElementById(id).src;
	var endung = source.search(/_over.gif/);
	if (endung != -1) {	
		var newsource = source.replace(/_over.gif/g, ".gif");
		var newimage = new Image();
  } else {
    var newsource = source.replace(/_over.jpg/g, ".jpg");
		var newimage = new Image();
  }		
	newimage.src = newsource;
	document.getElementById(id).src = newimage.src;
	// TextCheck
	VisibilitySwitchText(id);
}