<link rel="stylesheet" type="text/css" href="../../codebase/skins/dhtmlxform_dhx_skyblue.css">
    <script src="../../codebase/dhtmlxcommon.js"></script>
    <script src="../../codebase/dhtmlxform.js"></script>
    <style>
        div#simpleLog {
            width: 500px;
            height: 200px;
            font-family: Tahoma;
            font-size: 11px;
            overflow: auto;
        }
        span.allow {
            color: green;
        }
        span.deny {
            color: red;
        }
    </style>
    <script>
var myForm,
formData,
logObj;
function doOnLoad() {
    formData = [{
        type: "settings",
        position: "label-right"
    }, {
        item: "label",
        label: "Some checkboxes"
    }, {
        type: "checkbox",
        name: "ch_allow",
        value: "value_allow",
        label: "This checkbox is allowed to be changed"
    }, {
        type: "checkbox",
        name: "ch_deny",
        value: "value_deny",
        label: "This checkbox - NOT"
    }
];
    myForm = new dhtmlXForm("myForm", formData);
    myForm.attachEvent("onBeforeChange", function(name, value, is_checked) {
        var status = (name.search(/allow/) >= 0);
        logEvent("onBeforeChange, item name '" + name + "', value '" + value + "', is checked '" + (is_checked ? "true": "false") + "', " + (status ? "<span class='allow'>": "<span class='deny'>not ") + "change</span><br>");
        return status;
    });
    myForm.attachEvent("onChange", function(name, value, is_checked) {
        logEvent("onChange, item name '" + name + "', value '" + value + "', is checked '" + (is_checked ? "true": "false") + "'<br>");
    });
}
function logEvent(t) {
    if (!logObj)
        logObj = document.getElementById("simpleLog");
    logObj.innerHTML += t;
}
function clearLog() {
    if (!logObj)
        logObj = document.getElementById("simpleLog");
    logObj.innerHTML = "";
}</script>
 
 
    <table>
        <tr><td><div id="myForm"></div></td></tr>
        <tr><td><b>Log (<a href="javascript:void(0);" onclick="clearLog();">clear</a>)</b></td></tr>
        <tr><td><div id="simpleLog"></div></td></tr>
    </table>