function openportfolio(){
    var w,h;
    if (self.innerHeight){ // all except Explorer
        w = self.innerWidth;
        h = self.innerHeight;
    }
    else if (document.documentElement && document.documentElement.clientHeight){ // Explorer 6 Strict Mode
        w = document.documentElement.clientWidth;
        h = document.documentElement.clientHeight;
    }
    else if (document.body){ // other Explorers
        w = document.body.clientWidth;
        h = document.body.clientHeight;
    }

    var x,y;
    if (self.pageYOffset){// all except Explorer
        x = self.pageXOffset;
        y = self.pageYOffset;
    }
    else if (document.documentElement && document.documentElement.scrollTop){// Explorer 6 Strict
        x = document.documentElement.scrollLeft;
        y = document.documentElement.scrollTop;
    }
    else if (document.body){// all other Explorers
        x = document.body.scrollLeft;
        y = document.body.scrollTop;
    }                                                                                                                                                               
    
    if(!document.getElementById("containerportfolio")){
        var overlay = document.body.appendChild(document.createElement("div"));
        overlay.id = "containerportfolio";
        var closebutton = document.body.appendChild(document.createElement("div"));
        closebutton.id = "closebutton";
        closebutton.innerHTML = "SLUIT<br/>PORTFOLIO";
        closebutton.onclick= function(){
                overlay.style.display = 'none';
                this.style.display='none';
        }
        var so = new SWFObject("/gallery.swf", "portfolio", "100%", "100%", "6","#000000");
        so.addParam("wmode","transparent")
        so.write("containerportfolio");
    }
    var overlay = document.getElementById("containerportfolio")
    var closebutton = document.getElementById("closebutton")
    overlay.style.width=w-21+"px";
    overlay.style.height=h+"px";
    overlay.style.left=x+"px";
    overlay.style.top=y+"px";
    overlay.style.display = 'block';
    closebutton.style.top = (y+0.5*h-20)+"px";
    closebutton.style.left = (x+0.5*w-420)+"px";
    closebutton.style.display='block';
}