Hi,
Below is a sample. Answering your question, 'record' and 'index' arguments were added to the javascript function because i had seen it on a forum sample. Most likely i got it completely wrong. I was inserting a record after the first listitem, but this could have easily been before the firstitem.
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">
protected void Page_Load(object sender, EventArgs e)
{
this.Store1.DataSource = new object[]
{
new object[]{"AL", "Alabama", "The Heart of Dixie"},
new object[] { "AK", "Alaska", "The Land of the Midnight Sun"},
new object[] { "AZ", "Arizona", "The Grand Canyon State"},
new object[] { "AR", "Arkansas", "The Natural State"},
new object[] { "CA", "California", "The Golden State"},
new object[] { "CO", "Colorado", "The Mountain State"},
new object[] { "CT", "Connecticut", "The Constitution State"},
new object[] { "DE", "Delaware", "The First State"},
new object[] { "DC", "District of Columbia", "The Nation's Capital"},
new object[] { "FL", "Florida", "The Sunshine State"},
new object[] { "GA", "Georgia", "The Peach State"},
new object[] { "HI", "Hawaii", "The Aloha State"},
new object[] { "ID", "Idaho", "Famous Potatoes"},
new object[] { "IL", "Illinois", "The Prairie State"},
new object[] { "IN", "Indiana", "The Hospitality State"},
new object[] { "IA", "Iowa", "The Corn State"},
new object[] { "KS", "Kansas", "The Sunflower State"},
new object[] { "KY", "Kentucky", "The Bluegrass State"},
new object[] { "LA", "Louisiana", "The Bayou State"},
new object[] { "ME", "Maine", "The Pine Tree State"},
new object[] { "MD", "Maryland", "Chesapeake State"},
new object[] { "MA", "Massachusetts", "The Spirit of America"},
new object[] { "MI", "Michigan", "Great Lakes State"},
new object[] { "MN", "Minnesota", "North Star State"},
new object[] { "MS", "Mississippi", "Magnolia State"},
new object[] { "MO", "Missouri", "Show Me State"},
new object[] { "MT", "Montana", "Big Sky Country"},
new object[] { "NE", "Nebraska", "Beef State"},
new object[] { "NV", "Nevada", "Silver State"},
new object[] { "NH", "New Hampshire", "Granite State"},
new object[] { "NJ", "New Jersey", "Garden State"},
new object[] { "NM", "New Mexico", "Land of Enchantment"},
new object[] { "NY", "New York", "Empire State"},
new object[] { "NC", "North Carolina", "First in Freedom"},
new object[] { "ND", "North Dakota", "Peace Garden State"},
new object[] { "OH", "Ohio", "The Heart of it All"},
new object[] { "OK", "Oklahoma", "Oklahoma is OK"},
new object[] { "OR", "Oregon", "Pacific Wonderland"},
new object[] { "PA", "Pennsylvania", "Keystone State"},
new object[] { "RI", "Rhode Island", "Ocean State"},
new object[] { "SC", "South Carolina", "Nothing Could be Finer"},
new object[] { "SD", "South Dakota", "Great Faces, Great Places"},
new object[] { "TN", "Tennessee", "Volunteer State"},
new object[] { "TX", "Texas", "Lone Star State"},
new object[] { "UT", "Utah", "Salt Lake State"},
new object[] { "VT", "Vermont", "Green Mountain State"},
new object[] { "VA", "Virginia", "Mother of States"},
new object[] { "WA", "Washington", "Green Tree State"},
new object[] { "WV", "West Virginia", "Mountain State"},
new object[] { "WI", "Wisconsin", "America's Dairyland"},
new object[] { "WY", "Wyoming", "Like No Place on Earth"}
};
this.Store1.DataBind();
}
</script>
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title>Comboboxes</title>
<link href="../../../../resources/css/examples.css" rel="stylesheet" type="text/css" />
</head>
<body>
<form runat="server">
<ext:ResourceManager runat="server" />
<script type="text/javascript">
var addItem = function(combo, record, index) {
combo.insertRecord(0, { Text: 'New Option', Value: '4' });
}
</script>
<ext:Store ID="Store1" runat="server">
<Reader>
<ext:ArrayReader>
<Fields>
<ext:RecordField Name="abbr" />
<ext:RecordField Name="state" />
<ext:RecordField Name="nick" />
</Fields>
</ext:ArrayReader>
</Reader>
</ext:Store>
<ext:GridPanel ID="_gridPanel1" runat="server" Frame="true" StoreID="Store1" Height="258" Width="726" SelectionMemory="Enabled" StripeRows="true">
<ColumnModel ID="ColumnModel1" runat="server">
<Columns>
<ext:Column ColumnID="abbr" DataIndex="abbr" Header="abbr" Width="68" />
<ext:Column ColumnID="state" DataIndex="state" Header="state" Width="68" />
<ext:Column ColumnID="nick" DataIndex="nick" Width="92" Align="Left" Fixed="true" Sortable="false" MenuDisabled="true" Resizable="false">
<Editor>
<ext:ComboBox ID="_options" runat="server" EmptyText="Options" TriggerAction="All">
<Items>
<ext:ListItem Text="Option 1" Value="1" />
<ext:ListItem Text="Option 2" Value="2" />
<ext:ListItem Text="Option 3" Value="3" />
</Items>
<Listeners>
<addItem Handler="onSelect" />
</Listeners>
</ext:ComboBox>
</Editor>
</ext:Column>
</Columns>
</ColumnModel>
<View>
<ext:GridView ID="_gridView1" runat="server" ForceFit="false" />
</View>
<BottomBar>
<ext:PagingToolBar ID="_pagingToolBar1" runat="server" PageSize="8" StoreID="_store1" DisplayInfo="true" DisplayMsg="Displaying {0} - {1} of {2} records" EmptyMsg="Nothing to display" Visible="true" />
</BottomBar>
<LoadMask ShowMask="true" />
<Plugins>
<ext:EditableGrid ID="_editableGrid1" runat="server" />
</Plugins>
</ext:GridPanel>
</form>
</body>
</html>