How to pass additional parameter to kendo template with out overriding datasource parameter

I am trying to pass additional parameter to template via:

  detailTemplate: kendo.template($("#detail-template").html())({someParam: 'someValue'})

However when I do this, I can't no more use variables coming from data source. When I uncomment those variables it gives error(see console output)

   <div>
    Name: #: /*name*/ #
  </div>
  <div>
    Age: #: /*age*/ #
  </div>

How can I use both datasource variables and external variable in kendo template?

Solution

detailTemplate: function(dataItem){ 
    dataItem.someParam = 'someValue';
    return kendo.template($("#detailTemplate").html())(dataItem);
}