试试看这个，可能和你的要求不一样，但是可是实现一样的功能

function findInPage(str) {
    var txt, i, found;
    if (str == "")
    return false;
    if (NS4) {
    if (!win.find(str))
        while(win.find(str, false, true))
        n++;
    else
        n++;
    if (n == 0)
        alert("没发现你要找的！");
    }
    if (IE4) {
    txt = win.document.body.createTextRange();
    for (i = 0; i <= n && (found = txt.findText(str)) != false; i++) {
        txt.moveStart("character", 1);
        txt.moveEnd("textedit");
    }
    if (found) {
        txt.moveStart("character", -1);
        txt.findText(str);
        txt.select();
        txt.scrollIntoView();
        n++;
    }
    else {
        if (n > 0) {
        n = 0;
        findInPage(str);
        }
        else
        alert("没发现你要找的！");
    }
    }
    return false;
}