I am using someones code but itt deosnt work in IE(works fine in FireFox) and im getting the error: 'filters.alpha' is null or not an object can anyone tell me why?

Please post the code

here you go

JSFX.ImageFadeAnimation = function()
{
	JSFX.ImageFadeRunning = false;
	for(i=0 ; i<document.images.length ; i++)
	{
		var img = document.images[i];
		if(img.state)
		{
			if(img.state == "FADE_IN")
			{
				img.index+=FadeInStep;

				if(img.index > 100)
					img.index = 100;

				if(img.filters)
					img.filters.alpha.opacity = img.index;
				else
					img.style.MozOpacity = img.index/101;

				if(img.index == 100)
					img.state="ON";
				else
					JSFX.ImageFadeRunning = true;
			}
			else if(img.state == "FADE_IN_OUT")
			{
				img.index+=FadeInStep;
				if(img.index > 100)
					img.index = 100;

				if(img.filters)
					img.filters.alpha.opacity = img.index;
				else 
					img.style.MozOpacity = img.index/101;

	
				if(img.index == 100)
					img.state="FADE_OUT";

				JSFX.ImageFadeRunning = true;
			}
			else if(img.state == "FADE_OUT")
			{
				img.index-=FadeOutStep;
				if(img.index < 0)
					img.index = 0;

				if(img.filters)
					img.filters.alpha.opacity = img.index;
				else
					img.style.MozOpacity = img.index/101;


				if(img.index == 0)
					img.state="OFF";
				else
					JSFX.ImageFadeRunning = true;
			}
			else if(img.state == "FADE_OUT_IN")
			{
				img.index-=FadeOutStep;
				if(img.index < 0)
					img.index = 0;

				if(img.filters)
					img.filters.alpha.opacity = img.index;
				else
					img.style.MozOpacity = img.index/101;

				if(img.index == 0)
				{
					img.src = img.next_on;
					img.currSrc = img.next_on;
					img.state="FADE_IN";
				}
				JSFX.ImageFadeRunning = true;
			}
		}
	}
	/*** Check to see if we need to animate any more frames. ***/
	if(JSFX.ImageFadeRunning)
		setTimeout("JSFX.ImageFadeAnimation()", JSFX.ImageFadeInterval);
}

I do not recongnize this code:


JSFX.

I am thinking, javascript Effect??

Its possible that this will only work in firefox.

Anyone else have an idea?

img.filters.alpha.opacity = img.index;

change this line to read:
img.style.filter = 'alpha(opacity='+img.index+')';

Are you using a correct and valid doctype?
and, if you are using XHTML1.n do you have the <? xml ...> declaration above it? because that will negate the doctype for IE.

posting a URI so we can see the issue directly would be helpful.