vb.net - Asp.Net UpdatePanel not working -

hi having problems getting update panel function correctly in web page. have text box in user enters id hits return key populate text box address. page work's on chrome , firefox, in ie , safari each time press return key new row added volume amount. have tried overcome problem using update panel update id , address text boxes no matter new row added volume.

anyone see going wrong

<asp:content id="content2" contentplaceholderid="maincontent" runat="server"> <table border="1" width="960px">   <ajaxtoolkit:toolkitscriptmanager id="toolkitscriptmanager1" runat="server"></ajaxtoolkit:toolkitscriptmanager>  <asp:updatepanel runat="server" id="updatepanel" updatemode="conditional">  <triggers>        <asp:asyncpostbacktrigger controlid="button1" eventname="click" />  </triggers>  <contenttemplate>   <tr>     <td rowspan="1">customer account code</td>              <td><asp:textbox id="txtcustomercode" runat="server" placeholder="enter code press return" /></td>          <asp:button id="button1" runat="server" onclick="button1_keydown"  style="display: none" />          <td rowspan="1" colspan="1"><asp:dropdownlist id="dropdownlistselectaddress" class="dropdownlistselectaddress" runat="server"  autopostback = "true" onselectedindexchanged = "selectedindexchanged"></asp:dropdownlist></td>   </tr>   <tr>     <td>customer account</td>     <td colspan="1" width="300px"><asp:textbox id="txtcustomer" width="300px" runat="server" ></asp:textbox></td>     <td rowspan="4" colspan="1"><asp:textbox id="selectedaddresstextbox" class="selectedaddresstextboxnq"  width="430px" textmode="multiline" runat="server"></asp:textbox></td>   </tr>   <tr>         <td colspan="1">customer part number/description</td>         <td colspan="2"><asp:textbox id="txtcustomerpartnumber" runat="server"></asp:textbox></td>   </tr>   <tr>         <td colspan="1">sales person</td>         <td colspan="1"><asp:textbox id="tbsalesperson" runat="server"></asp:textbox></td>   </tr>   <tr>         <td colspan="1">end customer</td>         <td colspan="1"><asp:dropdownlist id="dbendcustomer" width="100px" runat="server" onselectedindexchanged="fillselectedaddresstextbox"></asp:dropdownlist></td>   </tr>   </contenttemplate> </asp:updatepanel>     <tr>         <td colspan="1" valign="top">annual volume</td>         <td colspan="2"><asp:table width="300" id="table1" runat="server"  ></asp:table>                                     <asp:button id="btnaddvolume" class="btnaddvolume" runat="server" text="add volume"/>                                                 <asp:button id="btnremovevolume" class="btnremovevolume" runat="server" text="remove volume"/></td>   </tr> 

sub generates volume table.

protected sub generatetable(noofrows integer)     dim table table     dim row tablerow     dim cell tablecell     dim tb textbox     dim lbl label     table = table1     table.id = "table1"      'page.form.controls.add(table)     integer = 1 noofrows step 1         row = new tablerow()         j integer = 0 1 step 1             cell = new tablecell()             if j = 1                 tb = new textbox()                 tb.id = "textboxrow_" & & "col_" & j                 cell.controls.add(tb)             elseif j = 0                 lbl = new label()                 lbl.id = "label" &                 lbl.text = "volume " &                 cell.controls.add(lbl)             end if               row.cells.add(cell)         next         table.rows.add(row)     next      'setprevioustabledata(noofrows)     viewstate("rowscount") = noofrows     session("rowscount") = noofrows  end sub 

initialization sub

protected sub page_init(byval sender object, byval e system.eventargs) handles me.init     dropdownlistselectaddress.visible = false     dim menu menu = ctype(me.master.findcontrol("menu2"), webcontrols.menu)     menu.items(4).text = "logout"     if ispostback         dim table table         dim rowcount integer         dim messagestring         messagestring = getpostbackcontrolname()         ' msgbox(messagestring)         noofrows = session("rowscount")         if messagestring = "btnaddvolume"             noofrows = noofrows + 1         end if         if messagestring = "btnremovevolume"             noofrows = noofrows - 1         end if         if noofrows = 0             clientscript.registerstartupscript(me.gettype(), "alert", "alert('must have @ least 1 volume');", true)             noofrows = noofrows + 1         end if         generatetable(noofrows)         table = table1         rowcount = table.rows.count         'dim volume1 textbox         'volume1 = table.rows(0).cells(1).findcontrol("textboxrow_" & 1 & "col_" & 1)         ' volume1 = page.findcontrol("textboxrow_1col_1")     end if end sub 

page_load sub

protected sub page_load(byval sender object, byval e system.eventargs) handles me.load     if not ispostback         dbcolour.autopostback = true         dbcurrency.autopostback = true         dbcutters.autopostback = true         dbendcustomer.autopostback = true         dbmanusite.autopostback = true         dbmaterial.autopostback = true         filldropdowns()         generatetable(noofrows)         selectedaddresstextbox.text = ""     else         ' dim table table         '  table = table1         '  dim volume1 textbox         '  volume1 = table.rows(0).cells(1).findcontrol("textboxrow_" & 1 & "col_" & 1)         '  msgbox(volume1.text)     end if       dim menu menu = ctype(me.master.findcontrol("menu2"), webcontrols.menu)     menu.items(4).text = "logout"      if menu.items(4).selected         session.clear()         formsauthentication.signout()         response.redirect("default.aspx")     end if  end sub