function getPostalCode(k, e){
    var keyID = (window.event) ? event.keyCode : e.keyCode;
    var shiftKey = (window.event) ? event.shiftKey : e.shiftKey;
    var postalCode = '';
    if(((keyID >=48 && keyID <= 57) || (keyID >=96 && keyID <= 105)) && !shiftKey){
    //cyfry
        var j = k<4 ? k+1 : k;
        document.getElementById('postCode' + j).focus();
        for(var i=0; i<5; i++){
            postalCode += document.getElementById('postCode' + i).value;
            if(i == 1){
               postalCode += '-';
            } 
        }
        document.getElementById('postalCode').value = postalCode;
        return;
    }
    
    var field = document.getElementById('postCode' + k); 
    if(!field.value.match(/\d{1}/)){
        field.value = '';
    }
}