//===============================================
//validate forms

    function checkForm(form_id,items){

        var message = "";

        var form = document.getElementById(form_id);

        for(var i=0; i<items.length; i++){
            var item = form.elements[items[i].id];
            var item_type = (item.type == null)? "undef" : item.type;

            switch(item_type){
                case "select-one":
                    if (item.selectedIndex == -1 || item.options[item.selectedIndex].text == ""){
                        message += " - " + items[i].label + "\n";
                    }
                    break;

                case "select-multiple":
                    if (item.selectedIndex == -1){
                        message += " - " + items[i].label + "\n";
                    }
                    break;

                case "text":
                case "textarea":
                    var empty_string    = /^\s*$/;
                    if(empty_string.test(item.value)){
                        message += " - " + items[i].label + "\n";

                    } else if(item.id == "email"){
                        var check1      = /^[^@]+@[^@.]+\.[^@]*\w\w$/;
                        var check2      = /^[A-Za-z][\w.-]+@\w[\w.-]+\.[\w.-]*[A-Za-z][A-Za-z]$/;
                        var text        = trim(item.value);

                        if(!check1.test(text)){
                            message += " - " + items[i].label + " (unusual e-mail address)\n";
                        } else if(!check2.test(text)){
                            message += " - " + items[i].label + " (unusual e-mail address)\n";
                        }
                    }
                    break;

                default:
                    var checked = false;
                    for(var j=0; j<item.length; j++){ if(item[j].checked){ checked = true; } }
                    if (!checked){ message += " - " + items[i].label + "\n"; }

            }//switch(item.type)

        }//for(var i=0; i<items.length; i++)

        if(message != ""){
            message = "Please check the following required fields:\n" + message;
        } else {
            message = null;
        }

        return message;

    }//function checkForm(form_id,items)

//===============================================
//strip leading and trailing whitespace

    function trim(str){
        return str.replace(/^\s+|\s+$/g, '')
    };