function openwin() {
        window.open("beginner4_3pop01.html", "", "width=545,height=545,resizable=yes,scrollbars=yes" );
}
function openwin1() {
        window.open("beginner4_3pop02.html", "", "width=545,height=545,resizable=yes,scrollbars=yes" );
}
function openwin2() {
        window.open("beginner4_3pop03.html", "", "width=545,height=545,resizable=yes,scrollbars=yes" );
}