Textbox dimension inside Bootstrap Modal - textbox

Question

I have a textbox inside a Bootstrap Modal; here you can see an output example:
The yellow section is not part of original response; it's my add to show that the textbox has a default dimension and this one does not coincide with the modal size.
My purpose is to fill the yellow part with the textbox; in other words, I would that the textbox size coincide with the modal size. The question is: is there a way to perform this?
I add that in modal, the textbox is not part of form section, as you can see in the code:
<div id="myModal2" class="modal fade" role="dialog">
<div class="modal-dialog">
<div class="modal-content">
<div class="modal-header">
<button type="button" class="close" data-dismiss="modal">×</button>
<h4 class="modal-title">Editing Menu</h4>
</div>
<div class="modal-body">
<textarea id='areaforinfo' readonly></textarea>
<form id="updateeventsform2" class="form-horizontal">
<div class="form-group">
<label class="col-sm-2 control-label"
for="inputNotes">Notes</label>
<div class="col-sm-10">
<input type="text" class="form-control"
id="newnote" name ="newnote" placeholder="Put here the note"/>
</div>
</div>
<div class="form-group">
<label for = "type" class = "col-sm-2 control-label">Status</label>
<div class = "col-sm-10">
<select class = "form-control" id = "newstatus" name="newstatus">
<option value="open">open</option>
<option value="closed">closed</option>
</select>
</div>
</div>
</form>
</div>
</div>
<div class="modal-footer">
<button type="button" class="btn btn-secondary" data-dismiss="modal">Close</button>
<button type="submit" class="btn btn-primary" data-dismiss="modal">Save</button>
</div>
</div>
</div>
Should I put the textbox code inside form section?

Answer 1

Simply put the textbox inside the form and add the class attribute; the final result is:
<div class="modal-body">
<form id="updateeventsform2" class="form-horizontal">
<div class="form-group">
<label for='areaforinfo'>Message</label>
<textarea class = "form-control" id='areaforinfo' style="min-width: 100%" readonly></textarea>
</div>
</form>
</div>