Update data in Custom Table's Alternate Form

I have an alternate form in my custom table where I have a drop down. The values in the dropdown are populating through SQL query.

Select itemid,name from mytable  

When I press the submit button of the form, itemid value text is updated as name field text of my custom table.

So for example if my drop values are these below and I try to update the table row "Test2". Upon Updating the value, alternate form is updating 21 as a text in place of Test2

<select class="DropDownField form-control">
   <option value="0"> Please select</option>
   <option value="21">Test1</option>
   <option value="22">Test2</option>
   <option value="24">Test4</option>
</select>

How can I prevent that. Any suggestions would be helpful.

Thanks