Hi,

Repeaters do render but what you have specified them to. Pij t is to
generate the script to access the controls on repeaterItem, at least
generate an js array which contains the ClientIDs of the controls in the
repeater

It can be done for example iterating Repeater's Items collection, calling
FindControl against every RepeaterItem to get reference to the control on
the item. Then you can access ClientID of these controls

I have availbale a sample which deals with gridView but idea is 100% same.
item type is just RepeaterItem and you iterate Repeater's Items collection

protected void GridView1_PreRender(object sender, EventArgs e)
       {
           StringBuilder sbScript = new StringBuilder();

           //I'm doing this in PreRender because RowDataBound happens only
when databinding occurs - not necessarily on every request
           //and RowCreated is too early to get the correct client-side ID
           foreach(GridViewRow row in GridView1.Rows)
           {
               CheckBox CheckBox1 = (CheckBox)row.FindControl("CheckBox1");
               sbScript.Append("'");
               sbScript.Append(CheckBox1.ClientID);
               sbScript.Append("'");
               if(row.RowIndex != (GridView1.Rows.Count - 1))
                   sbScript.Append(",");

           }
           //Register the array
           Page.ClientScript.RegisterArrayDeclaration("checkBoxes",
sbScript.ToString());
       }.

Previous examplöe creates a javascript array named checkBoxes cointaining
reference of CheckBoxes with CheckBox1 on every GridViewRow. You can then
use these array at client to reference the checkboxes there.