<div class="modal-body">
    <div class="form-horizontal">
        <div class="form-group">
            <label class="sr-only" for="exampleInputAmount">Amount (in dollars)</label>
            <div class="input-group">
                <div class="input-group-addon">$</div>
                <input type="text" class="form-control" id="exampleInputAmount" placeholder="Amount">
                <div class="input-group-addon">.00</div>
            </div>
        </div>
    </div>
</div>