Unable to set date field to null in CRM 2016 javascript

Hi All,

Am facing an issue in setting null value to date field on save event. And trying to click on assign button and checking the date field value to set null. Hence trying achieve this functionality by java script on save event.

Please find my below code:

function Form_onsave() { 

var DateSet= Xrm.Page.getAttribute("new_dateset").getValue();

if (Xrm.Page.ui.getFormType() != 1 && DateSet != null) {

 DateSet.setValue(null);

 DateSet.setSubmitMode("always");

}

}

We all are aware when clicking on assign button, save operation will trigger.

Hence, I wrote this code to set the date field value as null when assigning the lead record to another user.

But am getting an error saying, Error: Object doesn't support this action.

Can anyone please help why is it happening?

Thanks,

Punitha D