<form class="ng-pristine ng-invalid ng-invalid-required" advance-on-enter="" autocomplete="off" name="destroyForm" ng-submit="processDestroy()" novalidate="">
<div class="form-group">
<label>Ticket Number</label>
<input class="ng-isolate-scope ng-pristine ng-invalid ng-invalid-required" name="ticket" ng-model="destroyData.ticket" remote-validate="validateTicket" required="" type="text">
<span class="alert alert-error plain ng-hide" ng-show="destroyForm.ticket.$invalid &amp;&amp; destroyData.ticket.length > 0">Invalid Ticket Number</span>
</div>
<div class="form-group">
<label>Destruction Machine Tag</label>
<input class="ng-isolate-scope ng-pristine ng-invalid ng-invalid-required" autofocus="autofocus" name="bin_asset_tag" ng-model="destroyData.bin_asset_tag" remote-validate="validateBin" required="" type="text">
<span class="alert alert-error plain ng-hide" ng-show="destroyForm.bin_asset_tag.$invalid &amp;&amp; destroyData.bin_asset_tag.length > 0">Invalid Asset Tag</span>
</div>
<div class="form-group">
<label>Drive Serial Number</label>
<input class="ng-pristine ng-invalid ng-invalid-required" name="serial_id" ng-model="destroyData.serial_id" required="" type="text">
</div>
<div class="form-horizontal">
<input disabled="disabled" class="btn btn-primary btn-lg" ng-disabled="destroyForm.$invalid" type="submit">
</form>

var e = document.createElement('input');
e.type = 'button';
e.value = 'Start';
e.setAttribute('id', 'dbtn');
e.setAttribute('name', 'dbtn');
e.className = 'btn btn-primary btn-lg';
e.onclick = function startdestroy() {
      var serial_text = document.getElementsByName('serial_id')[1];
      //alert(serial_id);
      serial_text.value = “12345”;
      var sbtn=document.getElementsByClassName('btn btn-primary btn-lg') [1];
      sbtn.removeAttribute("disabled");
      //serial_text.removeAttribute("required")
      document.getElementsByClassName('btn btn-primary btn-lg') [1].click();
    }
  });
};
var inputdiv = document.getElementsByClassName('form-horizontal') [1];
inputdiv.appendChild(e);