function buttons(){
    if($("#1").is(":visible")){
        $("#prev").hide();
    }else{
        $("#prev").show();
    }
    if($("#<?php echo $anzahl; ?>").is(":visible")){
        $("#next").hide();
    }else{
        $("#next").show();
    }
}
buttons();

function next(){
    var firstvisible = $(".thumbprofilpic:visible:first").attr("id");
    var lastvisible = $(".thumbprofilpic:visible:last").attr("id");
    var shownextpic = parseInt(lastvisible) + 1;
    var hideprevpic = parseInt(firstvisible);
    $('#' + hideprevpic).hide();
    $('#' + shownextpic).show();
    var selected = '<img src="' + $('#' + lastvisible).attr('src') + '">';
    var bild = selected.replace("/klein/", "/normal/");
    $("#previewprofil").html(bild);
    buttons();
}

function prev(){
    var firstvisible = $(".thumbprofilpic:visible:first").attr("id");
    var lastvisible = $(".thumbprofilpic:visible:last").attr("id");
    var showprevpic = parseInt(firstvisible) - 1;
    var hidenextpic = parseInt(lastvisible);
    $('#' + showprevpic).show();
    $('#' + hidenextpic).hide();
    var selected = '<img src="' + $('#' + firstvisible).attr('src') + '">';
    var bild = selected.replace("/klein/", "/normal/");
    $("#previewprofil").html(bild);
    buttons();
}

function picid(z){
    var selected = '<img src="' + $(z).attr('src') + '">';
    var bild = selected.replace("/klein/", "/normal/");
    $("#previewprofil").html(bild);
}