// Diese Routinen und Algorithmen sind urheberlich geschützt (c) von Reinhard Doberstein, Mannheim; info@doberstein.com !
// This funktions are copyright (c) by Reinhard Doberstein, info@doberstein.com !

// var do_scroll = true;
var do_scroll_up = false;
var do_scroll_down = false;
SC_grenze = 6;
var delay = 100;
var ns =0;
var ie =0;
ns6 =0;
var dauerLoop = 0;

function nix()
{
}        // function nix()

function message(txt)
{
        Jetzt = new Date();
        window.defaultStatus = "" + txt + " " + Jetzt.toLocaleString();
}

function go_up()
{
  stop_scroll();
  if ( (ie == 1 && top && top.mitte && top.mitte.document && top.mitte.document.body) || ns == 1  ) {
//        do_scroll = true;
        do_scroll_up = true
        delay = 100;
        next_up();
  }
}        // function do_up()

function next_up()
{
        if ( (ie == 1 && top && top.mitte && top.mitte.document && top.mitte.document.body) || ns == 1 ) {
                top.mitte.scrollBy(0,-10);
                if (ns == 1) {
                        scroll_pos = top.mitte.pageYOffset;
                } else if (ie == 1 ){
                        scroll_pos = top.mitte.document.body.scrollTop;
                }
                if ( scroll_pos < 0 ) {
//                        do_scroll=false;
                        do_scroll_up = false;
                }
                if (do_scroll_up == true) {
                        delay -= 10;
                        if (delay < 10) {
                                delay = 10;
                        }
                setTimeout("next_up()", delay);
                }
        }
        doTest();
}        // function next_up()

function go_down()
{
  stop_scroll();
  if ( (ie == 1 && top && top.mitte && top.mitte.document && top.mitte.document.body) || ns == 1 ) {
//        do_scroll = true;
        do_scroll_down = true;
        delay = 100;
        next_down();
  }
}        // function do_down()

function next_down()
{
        if ( (ie == 1 && top && top.mitte && top.mitte.document && top.mitte.document.body) || ns == 1 ) {
                top.mitte.scrollBy(0,10);
                if (ns == 1) {
                        scroll_pos = top.mitte.pageYOffset;
                } else if (ie == 1 ){
                        scroll_pos = top.mitte.document.body.scrollTop;
                }
                if (ns == 1) {
                        yMax = top.mitte.window.document.height - top.mitte.window.innerHeight;
                } else if (ie == 1) {
                        yMax = top.mitte.document.body.scrollHeight - top.mitte.document.body.clientHeight;
                }
                if ( (yMax - scroll_pos ) < SC_grenze ) {
//                        do_scroll = false;
                        do_scroll_down = false;
                }
                if (do_scroll_down == true) {
                        if (delay > 10) {
                                delay -= 10;
                        }
                        setTimeout("next_down()", delay);
                }
        }
        doTest();
}        // function next_down()

function stop_scroll()
{
//  do_scroll = false;
  do_scroll_up = false;
  do_scroll_down = false;
}        // function stop_scroll()

function doTest()
{
        scroll_pos =0;

//        alert ("Nach doTest()");
//        if ( top.mitte.document.body ) {
//        if ( top != 0 && top.mitte != 0 && top.mitte.document != 0 && top.mitte.document.body != 0 ) {
          // alert ("top = " + top );
          // alert ("top.mitte = " + top.mitte );
          // alert ("top.mitte.document = " + top.mitte.document );  // Problem beim IE
          // alert ("top.mitte.document.body = " + top.mitte.document.body );  // Problem beim IE
         if ( (ie == 1 && top && top.mitte && top.mitte.document && top.mitte.document.body ) || ns == 1 ) {
        // if ( (ie == 1 && top && top.mitte ) || ns == 1 ) {
//                alert ("In doTest().loop");
                // bestimmen der aktuellen Scrollposition
                if (ns == 1) {
                        scroll_pos = top.mitte.pageYOffset;
                } else if (ie == 1 ){
                        scroll_pos = top.mitte.document.body.scrollTop;
                }
//                message ("Scrollposition: " + scroll_pos);

                // Button oben abchecken
                if (scroll_pos  <= 1 ) {
                        // open
                        if ( document.buttonUp.src.indexOf( "bilder/nix.gif") < 0 ) {
                                document.buttonUp.src = "bilder/nix.gif";
//                                document.buttonUp2.src = "bilder/nix.gif";
                                top.mitte.scrollTo(0,0);
                        }
                } else {
                        // irgendwo
                        if ( document.buttonUp.src.indexOf( "bilder/nix.gif" ) >= 0) {
                                document.buttonUp.src = "bilder/mover_up.gif";
//                                document.buttonUp2.src = "bilder/mover_up.gif";
                        }
                }

                // Button unten abchecken
                if (ns == 1) {
                        yMax = top.mitte.window.document.height - top.mitte.window.innerHeight;
                } else if (ie == 1) {
                        yMax = top.mitte.document.body.scrollHeight - top.mitte.document.body.clientHeight;
                }
//                window.defaultStatus = ("yMax = " + yMax + "; scroll_pos = " + scroll_pos );
                if ( (yMax - scroll_pos ) < SC_grenze ) {
                        if ( document.buttonDown.src.indexOf( "bilder/nix.gif") < 0 ) {
                                document.buttonDown.src = "bilder/nix.gif";
//                                document.buttonDown2.src = "bilder/nix.gif";
                                top.mitte.scrollTo(0,yMax);
                        }
                } else {
                        if ( document.buttonDown.src.indexOf( "bilder/nix.gif") >= 0 ) {
                                document.buttonDown.src = "bilder/mover_down.gif";
//                                document.buttonDown2.src = "bilder/mover_down.gif";
                        }
                }
        }
//        return 0;
}        // function doTest()

function startTest()
{
        doTest();
        dauerLoop = window.setInterval("doTest();",1000);
}        // function startTest()

if ((navigator.appName == "Netscape") && ( parseFloat(navigator.appVersion) >= 3.0 )  ) {
        ns = 1;
        if (parseFloat(navigator.appVersion) >= 5.0) {
          ns6 = 1;
        }
} else if ( (navigator.appName == "Microsoft Internet Explorer") && ( parseFloat(navigator.appVersion) >= 4.0 )  ) {
        ie = 1;
}
// do_scroll=false;