function create_cookie(name,value,days) {
    var expires;
    if (days) {
        var date = new Date();
        date.setTime(date.getTime()+(days*24*60*60*1000));
        expires = "; expires="+date.toGMTString();
    }
    else expires = "";
    document.cookie = name+"="+value+expires+"; path=/";
}

function read_cookie(name) {
    var nameEQ = name + "=";
    var ca = document.cookie.split(';');
    for(var i=0;i < ca.length;i++) {
        var c = ca[i];
        while (c.charAt(0)==' ') c = c.substring(1,c.length);
        if (c.indexOf(nameEQ) == 0) return c.substring(nameEQ.length,c.length);
    }
    return null;
}

function remove_cookie(name) {
    document.cookie = name+"=; expires=Thu, 01 Jan 1970 00:00:00 GMT; path=/";
}

function no_error(retrieved_data) {
    if (
        retrieved_data.substr(0, 11) != 'FATAL ERROR' &&
        retrieved_data.substr(0, 5) != 'error' &&
        retrieved_data.substr(0, 4) != 'fail' &&
        retrieved_data.substr(0, 26) != 'Notice: Undefined variable'
            ) return true;
    else return false
}

function get_radio_value(radio_object) {
    var radio_length = radio_object.length;
    if (radio_length == undefined) if (radio_object.checked) return radio_object.value; else return '';
    for (var i = 0; i < radio_length; i++) if (radio_object[i].checked) return radio_object[i].value;
    return '';
}

function switch_to_language(new_language) {
    var current_language = readCookie('current_language');
    if (new_language != current_language) {
        createCookie('current_language', new_language, 1);
        window.location.reload();
    }
}

function emailcheck(str) {

    var at="@";
    var dot=".";
    var lat=str.indexOf(at);
    var lstr=str.length;

    //no @, @ at the beggining or @ at the end
    if (str.indexOf(at)==-1 || str.indexOf(at)==0 || str.indexOf(at)==lstr) return false;

    //no ., . at the beggining or . at the end
    if (str.indexOf(dot)==-1 || str.indexOf(dot)==0 || str.indexOf(dot)==lstr) return false;

    //just one @
    if (str.indexOf(at,(lat+1))!=-1) return false;

    //. just before @ or ????
    if (str.substring(lat-1,lat)==dot || str.substring(lat+1,lat+2)==dot) return false;

    //dot after the @
    if (str.indexOf(dot,(lat+2))==-1) return false;

    //no spaces
    if (str.indexOf(" ")!=-1) return false;

    return true;
}