How To Access Repeater Item Template Controls Outside The Repeater

I am using a repater whose item template is having a dropdownlist. Now i want to access that dropdownlist from a button click event. Here is the code iam using :

protected void btn1_Click(object sender, EventArgs e)
{
foreach (RepeaterItem item in rptWord.Items)
{
DropDownList ddl1 = (System.Web.UI.WebControls.DropDownList)rptWord.FindControl("ddlWord");
}
}

But m getting ddl1 as null. For this i created a function which is as follows:

public void myFunction(object sender, RepeaterItemEventArgs e)
{
foreach (RepeaterItem item in rptWord.Items)
{
DropDownList la = (System.Web.UI.WebControls.DropDownList)e.Item.FindControl("ddlWord");
}
}

using this function iam able to access the repeater but i guess its not possible to call this function on button click event .