/* Browsererkennung
 ************************************************/

function ns4() {
    return (document.layers) ? true:false;
}

function dom() {
    return (document.getElementById) ? true:false;
}

/* Bildwechsel
 ************************************************/

function changeImg(name,src) {
    if (document.images) {
        document.images[name].src = src;
    }
}

/* Layer
 ************************************************/

function changeLayImg(layName,name,src) {
    if (document.images){
        if (ns4()) eval("document."+layName).document.images[name].src = src;
        else changeImg(name,src);
    }
}

function showObj(name) {
    if (ns4()) eval("document."+name).visibility = "show";
    else if (dom()) document.getElementById(name).style.visibility = "visible";
}

function hideObj(name) {
    if (ns4()) eval("document."+name).visibility = "hide";
    else if (dom()) document.getElementById(name).style.visibility = "hidden";
}

function getObjVisibility(name) {
    if (ns4()) {
        switch (eval("document."+name).visibility) {
            case "hide" : return -1;
            case "show" : return 1;
            default : return 0;
        }
    } else if (dom()) {
        switch (document.getElementById(name).style.visibility) {
            case "hidden" : return -1;
            case "visible" : return 1;
            default : return 0;
        }
    }
}

function moveObjTo(name,x,y) {
    if (ns4()) {
        if(x!='') eval("document."+name).left = x;
        if(y!='') eval("document."+name).top  = y;
    }
    else if (dom()) {
        if(x!='') document.getElementById(name).style.left = x;
        if(y!='') document.getElementById(name).style.top  = y;
    }
}

function clipObjTo(name,t,r,b,l) {
    if (ns4()) {
        eval("document."+name).clip.top = t;
        eval("document."+name).clip.right = r;
        eval("document."+name).clip.bottom = b;
        eval("document."+name).clip.left = l;
    }
    else if (dom()) document.getElementById(name).style.clip = "rect("+t+"px "+r+"px "+b+"px "+l+"px)"
}

/* Navigation
 ************************************************/

/* Ein- und Ausblenden des Login-Formulars */

function checkLoginStyle() {
    if(dom())
        if(document.getElementById("loginform") && document.getElementById("loginlink"))
            return (document.getElementById("loginform").style && document.getElementById("loginlink").style);
    return false;
}

function focusLogin() {
    if(checkLoginStyle()) {
        for(i=0;i<document.getElementById("loginform").elements.length;i++) {
            elem = document.getElementById("loginform").elements[i];
            elem.style.border = "solid 1px #000080";
            elem.style.backgroundColor = "white";
        }
        document.getElementById("loginlink").style.color = "#000080";
        document.getElementById("neulink").style.color   = "#000080";
    }
}

function unfocusLogin() {
    if(checkLoginStyle()) {
        for(i=0;i<document.getElementById("loginform").elements.length;i++) {
            elem = document.getElementById("loginform").elements[i];
            elem.style.border = "dashed 1px #5667B7";
            elem.style.backgroundColor = "#D6E7F7";
        }
        document.getElementById("loginlink").style.color = "#5667B7";
        document.getElementById("neulink").style.color   = "#5667B7";
    }
}

/* Jahrgänge: Drawer */

var drawerPos=-103, drawerHeight=200;
var d0=drawerPos, d1=drawerPos+drawerHeight;
var drawing = false;

function drawer() {
    if (drawing) return;
    target = (drawerPos==d0) ? d1 : d0;
    if(target==d0) changeImg("nav_layer","/img/nav_layer_down.gif");
    else changeImg("nav_layer","/img/nav_layer_up.gif");
    if ( ns4() || (dom() && document.getElementById("jahrgaenge").style && !window.opera) ) {
        moveDrawer(target);
    } else {
        if(target==d0) hideObj("jahrgaenge");
        moveObjTo("jahrgaenge","",target);
        drawerPos = target;
        if(target==d1) showObj("jahrgaenge");
    }
}

function moveDrawer(target) {
    drawing = true;
    if (drawerPos!=target) {
        dir = (drawerPos>target) ? -10 : 10;
        drawerPos+=dir;
        moveObjTo("jahrgaenge","",drawerPos);
        clipObjTo("jahrgaenge",d1-drawerPos,620,drawerHeight+10,0);
        showObj("jahrgaenge");
        window.setTimeout("moveDrawer("+target+")",50);
    } else {
        if(target==d0) hideObj("jahrgaenge");
        drawing = false;
    }
}

function goToSite( pfad, url ) {
    if(url!="")
        self.location.href = pfad+url;
}

/* Hilfe & FAQ
 ************************************************/

function oeffne_hilfe ( anweisung )
{
  hilfe = window.open("hilfe.php?"+anweisung,"Hilfe","width=500,height=500,top=100,left=200,resizable=yes,scrollbars=yes,toolbar=yes,status=yes");
  hilfe.focus();
}

/* Darstellung
 ************************************************/

var bg1 = "#EAF3FB";
var bg2 = "#D6E7F7";

function changeElementBgColor(elem,col) {
    if(dom() && !window.opera) {
        elem.style.backgroundColor = col;
    }
}

/* Lade-Prozedur
 ************************************************/

function init() {
    unfocusLogin();
}