ISSUE while accessing the value from fragment to controller

Hi ,

I am having the issue :

CalFragment.xml

<l:VerticalLayout>

  <Label text="From" labelFor="DP1" class="nestleSize nestletopPad1"/>

  <DatePicker id="frm1" placeholder="Enter Date ..."

  width="200px" class="nestleDatFieldBase "/>

  </l:VerticalLayout>

while i am acessing the value of id="frm1" for date picker in my sap.ui.controller("oct.view.Root) not able to accesss the value of  date picker

getting error undefined not a function

var input1 = sap.ui.getCore().byId("frm1").getValue();

Any idea

Br

Dibya