<div class="container-fluid">

    <div class="login-form well well-sm" style="margin-bottom: 0px">
        <h1 align="center"><img src="images/logo.png" height="50"/></h1>
        <br />
        <alert ng-repeat="alert in alerts" type="{{alert.type}}" close="closeAlert($index)">{{alert.message}}</alert>
        <form ng-submit="login()">
            <div class="form-group has-feedback has-feedback-left">
                 <input type="text" class="form-control" placeholder="Username" ng-model="params.username"/>
                <i style="top:0px;" class="form-control-feedback glyphicon glyphicon-user"></i>
            </div>
            <br />
            <div class="form-group has-feedback has-feedback-left">
                <input type="password" class="input form-control" placeholder="Password" ng-model="params.password" />
                <i style="top:0px;" class="form-control-feedback glyphicon glyphicon-lock "></i>
            </div>
            <br /> <br />
            <div class="text-center">
                <input type="submit" class="btn btn-primary btn-lg" value="Sign In" />
            </div>
        </form>
    </div>

</div>

<div class="container-fluid">

    <div class="login-form well well-sm" style="margin-bottom: 0px">
        <h1 align="center"><img src="images/logo.png" height="50"/></h1>
        <br />
        <alert ng-repeat="alert in alerts" type="{{alert.type}}" close="closeAlert($index)">{{alert.message}}</alert>
        <form ng-submit="login()">
            <div class="form-group has-feedback has-feedback-left">
                 <input type="text" class="form-control" placeholder="Login" ng-model="params.username"/>
                <i style="top:0px;" class="form-control-feedback glyphicon glyphicon-user"></i>
            </div>
            <br />
            <div class="form-group has-feedback has-feedback-left">
                <input type="password" class="input form-control" placeholder="Password" ng-model="params.password" />
                <i style="top:0px;" class="form-control-feedback glyphicon glyphicon-lock "></i>
            </div>
            <br /> <br />
            <div class="text-center">
                <input type="submit" class="btn btn-primary btn-lg" value="Sign In" />
            </div>
        </form>
    </div>

</div>

Improve wording to avoid confusions
Improve wording to avoid confusions