function resize_maintext ()
{
    var viewportwidth;
    var viewportheight;

    // the more standards compliant browsers (mozilla/netscape/opera/IE7) use window.innerWidth and window.innerHeight

    if (typeof window.innerWidth != 'undefined')
    {
      viewportwidth = window.innerWidth,
      viewportheight = window.innerHeight
    }

    // IE6 in standards compliant mode (i.e. with a valid doctype as the first line in the document)

    else if (typeof document.documentElement != 'undefined'
     && typeof document.documentElement.clientWidth !=
     'undefined' && document.documentElement.clientWidth != 0)
    {
       viewportwidth = document.documentElement.clientWidth,
       viewportheight = document.documentElement.clientHeight
    }

    // older versions of IE

    else
    {
       viewportwidth = document.getElementsByTagName('body')[0].clientWidth,
       viewportheight = document.getElementsByTagName('body')[0].clientHeight
    }

    var elemheight =  viewportheight - 370;
    if (have_image == 0) elemheight += 181;
    if (elemheight < 230) return;
    document.getElementById('maintext').style.height = elemheight + 'px';
}