Thanks for all your info.

I tried to make something similar, but not with strings, with objects. I wanted a function to set the alpha for a DIV.

It sounds like this:

Object.prototype.setAlpha = function (alpha) {
this.style.filter = ‘alpha(opacity: ‘ + alpha + ‘)’;
this.style.MozOpacity = alpha / 100;
this.style.KhtmlOpacity = alpha / 100;
this.style.opacity = alpha / 100;
}

and I call it with: bgDiv.setAlpha(80);

Works in FF but doesn’t in IE (6).
Anyway, the content of the function is irrelevant, as the call of the function itself is the problem and gives the error in IE.

Any ideas?