Angular js ng-model - angularjs

Question

There are two buttons, through which popup is opened,
I have input field in that popup and applied validations on that input field.
If I close the popup and clicks on second button then input value is already got filled, because I used same input field to reduce code.
How to reset that ng-model value of input field?
I tried to set it null on click of close button, but after clicking on second button it set null but shows valiation errors on first time.
How to achieve this functionality using same input field?
<form name="vm.pvtZipCodeSearchForm" id="pvtZipCodeSearchForm" class="clearfix">
<div class="alert alert-danger" ng-if="vm.errorMsg">{{vm.InvalidAddressError}}</div>
<fieldset class="form-control form-control-wrapper">
<div class="fields">
<input type="text" class="form-control" placeholder="{{vm.lang.tcZipCode}}Postnummer*" title="{{vm.lang.tcZipCode}}*" name="zipCode" maxlength="5" ng-model="vm.tariff.zipCode" ng-maxlength="5" ng-minlength="5" ng-required="!disable" />
<div ng-if="vm.isValidForm" class="error-message" ng-messages="vm.pvtZipCodeSearchForm.zipCode.$error" role="alert">
<div ng-message="required">{{vm.lang.errMsgBlankField}}</div>
<div ng-message="minlength">{{vm.lang.errMsgShortField}}</div>
<div ng-message="maxlength">{{vm.lang.errMsgLongField}}</div>
</div>
</div>
<br />
<div class="fields tac">
<button type="button" ng-click="vm.tcSearchZipCode()" class="tc___button--search">{{vm.lang.search}}</button>
</div>
</fieldset>
</form>

Answer 1

You can try setting
vm.pvtZipCodeSearchForm.zipCode.$pristine = true;