function about() {

window.open("http://www.wattmusicclub.cz/flyer/flyer.html", "Pozvánka", "width=500, height=650");  
}

function about2() {

window.open("http://www.wattmusicclub.cz/flyer/flyer_2.html", "Pozvánka", "width=500, height=630");  
}

function about3() {

window.open("http://www.wattmusicclub.cz/flyer/flyer_3.html", "Pozvánka", "width=500, height=630");  
}

function about4() {

window.open("http://www.wattmusicclub.cz/flyer/flyer_4.html", "Pozvánka", "width=440, height=620");  
}

function about5() {

window.open("http://www.wattmusicclub.cz/flyer/flyer_5.html", "Pozvánka", "width=440, height=620");  
}