function change01() {
        document.big_pic.src = document.p1.src
    }

    function change02() {
        document.big_pic.src = document.p2.src
    }

    function change03() {
        document.big_pic.src = document.p3.src
    }
    function change04() {
        document.big_pic.src = document.p4.src
    }
    function change05() {
        document.big_pic.src = document.p5.src
    }