i think you are using codeigniter , use form_dropdown
try
<?php echo form_dropdown('dropdown',array('name'=>'city','id'=>'city','value'=>$person_info->city),'name'); ?>
check this
Question
Adding Combobox in new customer form For country,state,city in point of sale using php
<div class="field_row clearfix">
<?php echo form_label($this->lang->line( 'common_city' ) . ':', 'city' ); ?>
<div class='form_field'>
<?php echo form_input(array( 'name'=>'city','id'=>'city','value'=>$person_info->city));?>
</div>
</div>
In this code it using text box instead of that i need to implement Combobox
Solution
i think you are using codeigniter , use form_dropdown
try
<?php echo form_dropdown('dropdown',array('name'=>'city','id'=>'city','value'=>$person_info->city),'name'); ?>
check this