alert return false on confirm true and return true on confirm false on a value exists in asp.net

inActiveAffiliates returns empty value.it doesnot enters in onTextChanged event

 function checkInActiveAffiliate() {
            var IsValid = false;
            var inActiveAffiliates = $('[id*=hdnInActiveAffiliates]').val();          
            if (parseInt(inActiveAffiliates) > 0) {
                if (confirm('Do you want to approve application which contains inactive affiliate?')) {
                    IsValid = true;
                }
            }
            return IsValid;
        }

<asp:ImageButton ID="ibtApprove" align="absmiddle" runat="server" ImageUrl="~/Images/btn_Approve.gif"
                                        ToolTip="Approve" OnClick="ibtApprove_Click" OnClientClick="return checkInActiveAffiliate()" Style="height: 18px; display: none">
                                    </asp:ImageButton>
<asp:TextBox ID="txtRequestedAffiliate" runat="server" CssClass="inpTxt" Width="90%" ReadOnly="true"
                                                   OnTextChanged="txtRequestedAffiliate_TextChange" AutoPostBack="true"></asp:TextBox>
<asp:HiddenField ID="hdnInActiveAffiliates" runat="server" />

 protected void ibtApprove_Click(object sender, ImageClickEventArgs e)
    {

        //string otherAffiliateName = txtRequestedAffiliate.Text;
        //int inActiveAffiliates = new BLRating().InActiveAAffiliateChecking(otherAffiliateName);
        //if (inActiveAffiliates > 0)
        //{
        //   // ScriptManager.RegisterStartupScript(this, this.GetType(), "script", "confirm('Do you want to approve application which contains in active affiliate?');", true);
        //    ScriptManager.RegisterStartupScript(this, this.GetType(), "script", "checkInActiveAffiliate();", false);
        //}
        int intSuccess = new BLRating().ApproveApplication(intAppNo, Session["UserId"].ToString());
        if (intSuccess > 0)
        {
            Hashtable htLog = new Hashtable();
            htLog["AppNo"] = intAppNo.ToString();
            htLog["ActivityLogId"] = "28";
            htLog["Description"] = "Application BMO -" + intAppNo + " Approved";
            htLog["UserId"] = Session["UserId"].ToString();
            htLog["Status"] = hdnStatus.Value.ToString();
            new BLLogDetails().InsertLogDetails(htLog);
            Page.RegisterStartupScript("alert", "<script>Reload()</script>");
        }
    }
    protected void txtRequestedAffiliate_TextChange(object sender, EventArgs e)
    {
        string otherAffiliateName = txtRequestedAffiliate.Text;
        int inActiveAffiliates = new BLRating().InActiveAAffiliateChecking(otherAffiliateName);
        hdnInActiveAffiliates.Value = inActiveAffiliates.ToString();
    }

this is the code used