function validate_name(field,alerttxt){
    with (field){
        if(value.length==0){
            alert(alerttxt);
            return false;
        }else{
            return true;
        }

    }
}

function validate_email(field,alerttxt){
    with (field){
        apos=value.indexOf("@");
        dotpos=value.lastIndexOf(".");
        if (apos<1||dotpos-apos<2){
            alert(alerttxt);
            return false;
        }else{
            return true;
        }
    }
}

function validate_phone(field,alerttxt){
    with (field){
        if(value.length==0){
            alert(alerttxt);
            return false;
        }else{
            return true;
        }

    }
}

function validate_form(thisform){
    with (thisform){
        if (validate_name(name,"Podaj imię i nazwisko")==false){
            name.focus();
            return false;
        }

        if (validate_email(email,"Niepoprawny adres email")==false){
            email.focus();
            return false;
        }

        if (validate_phone(phone,"Podaj numer telefonu")==false){
            name.focus();
            return false;
        }
    }
}