Getting actual height of an auto-heighted element in IE

Answer 1

As a completion for Marc's answer; There's an equal for jQuery's height() in Prototype:

$('col1').getDimensions().height //or .width ofcourse

And here's the docs: http://prototypejs.org/api/element/getDimensions

Update: I agree with crescentfresh below. Since I had the absolute same problem in the past, I've searched all possible methods to find the dimension properties but I failed as you will. please take a look at this:

function getStyle(oElm, strCssRule){
    var strValue = "";
    if(document.defaultView && document.defaultView.getComputedStyle){
        strValue = document.defaultView.getComputedStyle(oElm, "").getPropertyValue(strCssRule);
    }
    else if(oElm.currentStyle){
        strCssRule = strCssRule.replace(/\-(\w)/g, function (strMatch, p1){
            return p1.toUpperCase();
        });
        strValue = oElm.currentStyle[strCssRule];
    }
    return strValue;
}

As you see, the function has been written to get the computed rendered current style of an element, but in our case even this method will fail, I guess. (worth a try)

So, as crescentfresh said, you have to find the problem in your CSS positioning method while not wasting your time seeking for a proper javascript function which could be able to do the magic. let's begin by removing that #content DIV and letting the #main to be the only wrapper of said columns, and then styling the remain to achieve the desired goal.