VS 2010 - Accessing Data From Dynamically Created DropdownLists

I have it setup so that when a user selects an item from a DropdownList, that some DropdownLists are dynamically created, based on the results from the Database that are returned after selecting the item in the first DropDownList.

Then, I have a button that takes the data and saves it to an object I've created for this, and I try to iterate through the Controls of the Placeholder that I added the DropdownList controls to.

However, the Placeholder says there are no controls in it, when I press the button, but I can obviously see them there.

Here is some code:

When a "Pilot" is selected, I get all of the Upgrade Types that that "Pilot" has access to, then I create a DropdownList for each type of Upgrade with all the actual Upgrades of that Type:

VB Code:
For Each u As UpgradeTypeList In upgrades           
Dim lbl As New Label           
Dim ddl As New DropDownList            
ddl.AutoPostBack = False            

[Code] ....

Then, when the "Add Squad Member" button is pressed, I am trying to iterate through the controls, pick out any DropdownLists and get the values from them and add them to a List Of in an object for the Pilot info:

VB Code:
Protected Sub btnAddSquadMember_Click(sender As Object, e As EventArgs) Handles btnAddSquadMember.Click   
For Each c As Control In rowUpgrades.Controls           
If TypeOf c Is DropDownList Then               
Dim DoesExist As Boolean = False                

[Code] ....

But, the controls supposedly don't exist and no values get added to the List(Of).