Web Forms :: Why CheckBox Is Not Getting Checked On OnCheckedChanged

I have a CheckBox field inside a Formview.

<asp:FormView ID="_fvApplicant" runat="server" DefaultMode="Edit" OnItemDeleting="ApplicantItemDeleting" Width="100%" DataSourceID="_dsApplicant" ondatabound="ApplicantFormBound">
<asp:CheckBox ID="_chkSuitable" OnCheckedChanged="test" AutoPostBack="true" CausesValidation="true" runat="server" Checked='<%# Bind("Suitable") %>' /></td>

In my Code Behind in test method I am trying to set the checked to true, but in the ApplicantFormBound event when i debug it is never true...any reasons why? Basically I want to set the Validator to true when checked.

protected void test(object sender, EventArgs e)
{
CheckBox vld = (CheckBox)_fvApplicant.FindControl("_chkSuitable");
vld.Checked = true;
_fvApplicant.DataBind();
}
protected void ApplicantFormBound(object sender, EventArgs e)
{
var chk = (CheckBox)_fvApplicant.FindControl("_chkSuitable");
if (chk != null)
{........