I am using the following code to set image transparency in Javascript, but it only works in Internet Explorer (and in FireFox, Opera, Safari and Google Chrome it remains non-transparent):

```
img = new Image();

img.src = "...";

img.style.filter       = "alpha(opacity=75);";
img.style.MozOpacity   = "0.75;";
img.style.opacity      = "0.75;";
img.style.KhtmlOpacity = "0.75;";

```

Can you please help?