Issue in SharePoint:DateTimeControl

I am putting alert when there is no date selected in SharePoint:DateTimeControl. My code is like

    if ($("[id$='DateTimeFrom']").val() == null)
         {
              alert("Please select From Date.");
              return false;
          }

        else if ($("[id$='DateTimeTo']").val() == null) {
            alert("Please select To Date.");
            return false;
        }
       else
        { 
          return true;
        }

But though i am entering the date in DateTimeFrom, it gives me the alert.