function getInternetExplorerVersion()
// Returns the version of Internet Explorer or a -1
// (indicating the use of another browser).
{
    var rv = -1; // Return value assumes failure.
    if (navigator.appName == 'Microsoft Internet Explorer') {
        var ua = navigator.userAgent;
        var re = new RegExp("MSIE ([0-9]{1,}[\.0-9]{0,})");
        if (re.exec(ua) != null)
            rv = parseFloat(RegExp.$1);
    }
    return rv;
}

function checkVersion() {
    var useIE6 = false;
    var ver = getInternetExplorerVersion();
    if (ver > -1) {   //IE
        if (ver < 7) {
            useIE6 = true;
            var i, a, main;
            for (i = 0; (a = document.getElementsByTagName("link")[i]); i++) {
                if (a.getAttribute("rel").indexOf("style") != -1 && a.getAttribute("href").indexOf("ie7") != -1) {
                    //a.href = a.href.replace("ie7", "ie6");
                    //alert(a.href);
                }
            }
        }
    }
    
    for (i = 0; (a = document.getElementsByTagName("link")[i]); i++) {
        if (a.getAttribute("rel").indexOf("style") != -1) {
          if ( useIE6 ) 
          {
            if ( a.getAttribute("href").indexOf("ie7") != -1)
            {
              a.disabled = true;
              //alert(a.href);
            }
          }
          else
          {
            if ( a.getAttribute("href").indexOf("ie6") != -1)
            {
              a.disabled = true;
              //alert(a.href);
            }
          }
        }
    }
}

checkVersion();