Infinite Scroll in angular UI Modal - angularjs

Question

I am trying to use infinite scroll in a angular UI modal and the modal is defined in ng-template as shown below
<script type="text/ng-template" id="someID" >
<div infinite-scroll="loadMoreEmployees()" infinite-scroll-distance="1">
<div class="modal-header">
<div class="vertical-margin row">
<div class="col-lg-12">
<h2 class="help-block">Departments assign</h2>
</div>
</div>
</div>
<div class="modal-body">
<div class="content-container">
<div class="col-lg-12 col-md-12 simple-data-table-content">
<table data-ng-if="vm.employees!=null || vm.employees.length!=0" class="table table-condensed text-center clear-bottom">
<tbody>
<tr>
<th>Employee No</th>
<th>Employee Name</th>
<th>Email</th>
<th data-ng-repeat="DeptType in vm.DeptTypes track by $index">{{DeptType.name}}</th>
<th></th>
</tr>
<tr data-ng-if="vm.employees==null || vm.employees.length==0"><td colspan="{{vm.DeptTypes.length + 4}}"></td></tr>
<tr data-ng-repeat="employee in vm.employees | limitTo:vm.loadEmployeeLimitCount" data-ng-if="vm.employees!=null && vm.employees.length > 0">
<td class="">{{employee.employeeNumber}}</td>
<td class="">{{employee.name}}</td>
<td class="">{{employee.email}}</td>
<td class="" data-ng-repeat="DeptType in vm.DeptTypes">
<input type="text" only-digits data-ng-model="employee.DeptSummary[DeptType.id]" style="width:50px;" min="1" />
</td>
</tr>
</tbody>
</table>
</div>
</div>
</div>
</div>
But infinite scroll as does not respond to scroll action, please point out where I am wrong.