Pass data (zoho record id) from Zoho CRM to Web tab widget

I'm developing a widget which will be hosted in zoho crm and open form button click. My question is how can i pass zoho record id (e.g. contact Id) from detail view page to a Webtab widget? I've tried using following JS SDK function which returns false.

var message = {
		arg1:"Argument 1",
		arg2:"Argument 2",
		arg3Nested:{
				subArg1:"SubArgument 1",
				subArg2:"SubArgument 2",
				subArg3:"SubArgument 3",
			}
}

ZOHO.CRM.UI.Widget.open({Entity:"WebTab1_Widget",Message:message})
.then(function(data){
    console.log(data)
})