var im_Array = new Array;
var im_names_Array = new Array('start','aktuelles','verein','zeitung','akv','buecherei','kalender','fotogalerie','fotoarchiv','publikationen','links','kontakt');

function getObjPos(imObj){
        var ix = null;
        var co = im_names_Array.length;
        for(i=0;i<co;i++){
                if(im_names_Array[i]==imObj){
                        ix = i;
                        break;
                }
        }
        return(ix);
}

function change_bt(im,action){

        var im_ix = getObjPos(im);
        var im_name = im+'_bt';

        if(document.all){
                document.images[im_name].src=im_Array[im_ix][action].src;
        }else if(document.layers){
                document.layers[im].document.images[im_name].src=im_Array[im_ix][action].src;
        }else{
                document.images[im_name].src=im_Array[im_ix][action].src;
                //document.getElementById(im_name).src=im_Array[im_ix][action].src;
        }
}

function preloadImages() {


          var pfad = 'img/';
        var anzahl = im_names_Array.length;

        for(i=0; i<anzahl; i++){

                var k = im_names_Array[i];
                var bt_ar = new Array(2);
                var im = pfad+'zero.gif';
                bt_ar[0] = new Image;
                bt_ar[0].src = im;
                var im = pfad+k+'_ro.gif';
                bt_ar[1] = new Image;
                bt_ar[1].src = im;

            im_Array[i] = bt_ar;
    }
}

preloadImages();