During ng-show the text is not appearing on ui - html

Question

During "ng-show" the text is not appearing on gui. Help me to say what is wrong in the code.
<div ng-app="myApp" ng-controller="myCntrl">
<form name="nishant" ng-submit="submit()">
<div>
Name : <input type="text" name="name" ng-minlenght="5"
required="required"> <span
ng-show="nishant.name.$error.minlength">required12</span>
</div>
<button name="button" type="submit">SUbmit</button>
</form>
<script type="text/javascript">
var app = angular.module("myApp", []);
app.controller("myCntrl", function($scope) {
alert("nishant");
$scope.submit = function() {
alert("in the submit");
}
});
</script>
</div>
Please see why ng-show is not appearing in the screen. If i am removing my controller it is appearing.

Answer 1

Update:
Final Code for showing messages using ng-show.
JSFiddle Demo
Answer:
You need to add a ng-model for using the form validators (nishant.name.$error.minlength). Also you have misspelt ng-minlength.
var app = angular.module('myApp', []);
app.controller('MyController', function MyController($scope) {
//alert("nishant");
$scope.submit = function() {
alert("in the submit");
}
});
<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.2.23/angular.min.js"></script>
<div ng-controller='MyController' ng-app="myApp">
<form name="nishant" ng-submit="submit()">
<div>
Name :
<input type="text" name="name" ng-minlength="5" required="required" ng-model="name"> <span ng-show="nishant.name.$error.minlength">required12</span>
</div>
<button name="button" type="submit">SUbmit</button>
</form>
</div>