I want the control of dropdown list value selection change. I want to stop the selected value change in the dropdownlist.

I have kendo dropdown list, on its triggering valueChange event.

```
<kendo-dropdownlist #dropdownlist required [data]="responseTypes" 
                                [defaultItem]="{responseTypeID: null, responseTypeName: 'Select Response Type'}"
                                [textField]="'responseTypeName'"
                                [valueField]="'responseTypeID'"
                                name="responseTypeId"
                                [(ngModel)]="selectedResponseType"
                                (valueChange)="responseTypeChange($event)"
                                #responseTypeIdVar="ngModel" class="form-control" style="width:180px;">

</kendo-dropdownlist>

```