if(window.addEventListener) {
    // Non-IE
    window.addEventListener("resize", set_bg, false);
} else {
    // IE
    window.attachEvent("onresize", set_bg);
}


minHeight = 680;

function set_bg(){
    if(self.innerWidth) {
          frameWidth = self.innerWidth;
          frameHeight = self.innerHeight;
    }
    else if(document.documentElement && document.documentElement.clientWidth){
          frameWidth = document.documentElement.clientWidth;
          frameHeight = document.documentElement.clientHeight;
    }
    else if(document.body){
          frameWidth = document.body.clientWidth;
          frameHeight = document.body.clientHeight;
    }


    if(frameHeight < minHeight){
        document.getElementById('main_bg').style.height = minHeight + "px";
    }
    else{
        document.getElementById('main_bg').style.height = "100%";
    }
    
}
function do_onload() {
    get_height();
    set_bg();
    set_active_menu();
    externalLinks();
}

window.onload = do_onload;

function get_height()
{
    var obj         =   document.getElementById('content');
    if(obj)
    {
        //  IE
        var obj_h   =   obj.offsetHeight;
        if(typeof(obj_h) !== 'number')
        {
            //  Moz
            var obj_h   =   document.defaultView.getComputedStyle(obj,"").getPropertyValue("height");
        }
        var obj_h       =   obj_h+400;
        minHeight       =   obj_h;
    }
}
function externalLinks() {
 if (!document.getElementsByTagName) return;
 var anchors = document.getElementsByTagName("a");
 for (var i=0; i<anchors.length; i++) {
   var anchor = anchors[i];
   if (anchor.getAttribute("href") &&
       anchor.getAttribute("rel") == "external")
     anchor.target = "_blank";
 }
}