How can I create a drop-down menu on the left side of my input text, featuring a '+' or '-' symbol?
For example: [+][input text]
<div class="form-group btm_border">
<label class="col-sm-4 control-label" for="first_name">
<?php echo translate('modify_amount') ?>
</label>
<div class="col-sm-6">
<div class="form-group" style="display:inline-block; float:none;">
<select class="selectpicker">
<option value="1">+</option>
<option value="2">-</option>
</select>
<input type="text" name="rebate_amount" id="rebate_amount" value="0" placeholder="0" class="form-control required">
</div>
</div>
</div>