function GetWindowSize() 
{
    try
    {
        var win = {width:0, height:0};
        
        if( typeof( window.innerWidth ) == 'number' ) 
        {
            //Non-IE
            win.width = window.innerWidth;
            win.height = window.innerHeight;
        } 
        else if( document.documentElement && ( document.documentElement.clientWidth || document.documentElement.clientHeight ) ) 
        {
            //IE 6+ in 'standards compliant mode'
            win.width = document.documentElement.clientWidth;
            win.height = document.documentElement.clientHeight;
        } 
        else if( document.body && ( document.body.clientWidth || document.body.clientHeight ) ) 
        {
            //IE 4 compatible
            win.width = document.body.clientWidth;
            win.height = document.body.clientHeight;
        }
        
        return win;
    }
    catch(e)
    {
        alert('Error in function \'GetWindowSize\' of module \'Helpers\':' + e.message + '!');
        throw 'Error in function \'GetWindowSize\' of module \'Helpers\':' + e.message + '!';
    }
}

function SetContainerHeights()
{
    try
    {
        var winSize = GetWindowSize();
        $('menu_holder').style.height = winSize.height + 'px';
        $('main_area').style.height = winSize.height - 120 + 'px';
        $('content_holder').style.height = winSize.height - 120 - 47 + 'px';
    }
    catch(e)
    {}
}

Event.observe(window, 'load', SetContainerHeights);
Event.observe(window, 'resize', SetContainerHeights);