nextsibling error in crm 2016

Hi All,

  I am using CRM 2016, the below function are not working in crm 2016, which were working in the CRM 2015.

In a  script i am using "nextsibling" , onsave of the form it is throwing an error("Unable to get property 'nextSibling' of undefined or null reference").Can anyone help me on this.

I'm using the below code.

// var_sc_optionset >>  Provide schema-name for Option Set field
// var_sc_optionsetvalue >> Provide schema-name for field which will store the multi selected values for Option Set
// OS >> Provide Option Set field object
// OSV >> Provide text field object which will store the multi selected values for Option Set

//Method to convert an optionset to multi select Option Set
// OS == parent.window.document.getElementById('new_productcategory'),"new_productcategoryvalue"
function ConvertToMultiSelect(var_sc_optionset, var_sc_optionsetvalue, OS, OSV) {
  //  debugger;
    if (OS != null && OSV != null) {
        OS.style.display = "none";
        Xrm.Page.getControl(var_sc_optionsetvalue).setVisible(false);

        // Create a DIV container
        var addDiv = document.createElement("div");
        addDiv.setAttribute("style", "overflow-y:auto; height:200px; border:1px #6699cc solid; background-color:#ffffff;");
        OS.parentNode.appendChild(addDiv);
        //  alert(OS.attributes.length);

        // Initialise checkbox controls
        if (OS != null) {
            var options = OS.getElementsByTagName("option");

            for (var i = 1; i < options.length; i++) {
                var pOption = options[i];

                var addInput = document.createElement("input");
                addInput.setAttribute("type", "checkbox");
                addInput.setAttribute("style", "border:none; width:25px; align:left;");
                if (IsChecked(pOption.text, OS, OSV)) {
                    addInput.setAttribute("checked", "checked");
                }

                var addLabel = document.createElement("label");
                addLabel.innerText = pOption.text;

                var addBr = document.createElement("br"); //it's a 'br' flag

                OS.nextSibling.appendChild(addInput);
                OS.nextSibling.appendChild(addLabel);
                OS.nextSibling.appendChild(addBr);
            }
            //   alert(OS.nextSibling.getElementsByTagName("input").length);
        }
    }
}


///////Supported functions

// Check if it is selected
function IsChecked(pText, OS, OSV) {
    //debugger;
    if (OSV.outerText != "--") {

        //alert(OSV.value);
        var OSVT = OSV.outerText.split(";");
        for (var i = 0; i < OSVT.length; i++) {
            if (OSVT[i] == pText)
                return true;
        }
    }
    return false;
}

// var_sc_optionsetvalue >> Provide schema-name for field which will store the multi selected values for Option Set
// OS >> Provide Option Set field object
// Save the selected text, this field can also be used in Advanced Find
function OnSave(OS, var_sc_optionsetvalue) {
 //   debugger;
    var getInput = OS.nextSibling.getElementsByTagName("input");
    var result = '';

    for (var i = 0; i < getInput.length; i++) {
        if (getInput[i].checked) {
            result += getInput[i].nextSibling.innerText + ";";
        }
    }

    //save value
    control = Xrm.Page.getControl(var_sc_optionsetvalue);
    attribute = control.getAttribute();
    attribute.setValue(result);
}

Regards,

Staya