Embed the jquery ui datepicker

Datepicker.js

var monthnames = [];
var daynames = [];
var dateFormat = 'dd.mm.yy';
var nextprev = [];


switch(lang) {
    case "de":
        monthnames = ['Januar','Februar','März','April','Mai','Juni','Juli','August','September','Oktober','November','Dezember'];
        daynames = ['So','Mo','Di','Mi','Do','Fr','Sa'];
        dateFormat = 'dd.mm.yy';
        nextprev = [];
        break;
    case "en":
        monthnames = ['January','February','March','April','May','June','July','August','September','October','November','December'];
        daynames = ['Su','Mo','Tu','We','Th','Fr','Sa'];
        dateFormat = 'dd/mm/yy';
        nextprev = [];
        break;
    case "cz":
        monthnames = ['Lednu','Únor','Breznu','Dubnu','Kvetnu','Cervnu','Cervenci','Srpnu','Zari','Rijnu','Listopadu','Prosinci'];
        daynames = ['Ne','Po','Út','St','Ct','Pá','So'];
        nextprev = [];
        break;
    case "dk":
        monthnames = ['januar','februar','mars','april','maj','juni','juli','august','september','oktober','november','desember'];
        daynames = ['so','ma','ti','on','to','fr','lo'];
        nextprev = [];
        break;
    case "nl":
        monthnames = ['Januari','Februari','Maart','April','Mei','Juni','Juli','Augustus','September','Oktober','November','December'];
        daynames = ['Zo','Ma','Di','Wo','Do','Vr','Za'];
        nextprev = [];
        break;
    case "ru":
        monthnames = ['January','February','March','April','May','June','July','August','September','October','November','December'];
        daynames = ['Su','Mo','Tu','We','Th','Fr','Sa'];
        nextprev = [];
        break;
    case "pl":
        monthnames = ['styczen','luty','marzec','kwiecien','maj','czerwiec','lipiec','sierpien','wrzesien','pazdziernik','listopad','grudzien'];
        daynames = ['Ni','Po','Wt','Sr','Cz','Pi','So'];
        nextprev = [];
        break;
    case "it":
        monthnames = ['Gennaio','Febbraio','Marzo','Aprile','Maggio','Giugno','Luglio','Agosto','Settembre','Ottobre','Novembre','Dicembre'];
        daynames = ['Do','Lu','Ma','Me','Gi','Ve','Sa'];
        nextprev = [];
        break;
    case "fr":
        monthnames = ['Janvier','Fevrier','Mars','Avril','Mai','Juin','Juillet','Aout','Septembre','Octobre','Novembre','Decembre'];
        daynames = ['Di','Lu','Ma','Me','Je','Ve','Sa'];
        nextprev = [];
        break;
}

$('#anreise').datepicker({
    minDate:0,
    dateFormat:dateFormat,
    firstDay:1,
    monthNames:monthnames,
    dayNamesMin:daynames
});