DataProviding to a particular DataGrid Column

Hi,

I have three columns in my Datagrid, in which I'm providing data for first two columns through XML / Webservice (I'm retrieving data from a database).

The database table does not have values to be passed to the third column, so I am trying to pass values to this particular column, how is it possible to do this?

<?xml version="1.0" encoding="utf-8"?>
<mx:Panel xmlns:mx="http://www.adobe.com/2006/mxml" borderColor="#587498" width="600" height="500" xmlns:test="n2.test.*" xmlns:ns1="n2.test.*" xmlns:custom="n2.WFU.components.*">
<mx:Script>
<![CDATA[
import mx.collections.XMLListCollection;
import mx.core.Application;
import mx.rpc.events.ResultEvent;

import mx.events.ListEvent;
import mx.events.DataGridEvent;
import mx.controls.Alert;
import mx.collections.ArrayCollection;
import n2.test.TestDataLoader;
import mx.controls.CheckBox;
import n2.vo.*;

private function InstituteSearch():void
{
var studentlist:Array=new Array();
studentlist=TestDataLoader.InstutesList.source;
TestDataLoader.MatchingInstitution.removeAll();
var isAdd:Boolean =true;
for each (var item3:Object in studentlist)
{
if(txtInstitution.text != "")
{
if(item3["Instution"].toString().indexOf(txtInstitution.text) > -1)
{
if(isAdd)
{
TestDataLoader.MatchingInstitution.addItem(item3);
isAdd=false;
}
}
}
isAdd = true;
}
}

private function UpdateData()
{
var item1:Object = dgTransactions.selectedItem;
Application.application.studentDetails.Instution.text = dgTransactions.selectedItem.Instution;
Application.application.studentDetails.Internal.text = dgTransactions.selectedItem.Inner;
Application.application.studentDetails.Ipdes.text = dgTransactions.selectedItem.Iped;
//Alert.show("updated successfully");
_xmlResult=null;
this.visible =false;
}
private function close():void{
_xmlResult=null;
//_xmlResult.INSTQueryServiceData=null;

this.visible=false;
}

[Bindable]private var _xmlResult:XML; //holds the result xml
private var result:XML;
[Bindable]private var _xlDayData:XMLList; //dataProvider for the day weather dataGrid
[Bindable]private var _sPlace:String;
[Bindable]private var val:ArrayCollection;
public var dataGridDataProvider:ArrayCollection=new ArrayCollection();

private function clickHandler():void
{
userRequest.INSTITUTIONQueryService.send(txtInstitution.text);
_xmlResult=null;
_xmlResult.INSTITUTIONQueryServiceData=null;
dgTransactions.dataProvider=_xmlResult.INSTITUTIONQueryServiceData;
}

private function getValue(e:ResultEvent):void
{
_xmlResult = XML(e.result);
// result=_xmlResult.INSTQueryServiceData;
Alert.show("Result :"+_xmlResult.toString());
dgTransactions.dataProvider=_xmlResult.INSTITUTIONQueryServiceData;
}
private function resetAll():void{
txtInstitution.text='';
}
/*for(var i:int = 0; i <_xmlResult.InstituteDetails.InstituteDetailValues.length(); i++) {
var insti:String=_xmlResult.InstituteDetails.InstituteDetailValues[i].institute;
var icode:String=_xmlResult.InstituteDetails.InstituteDetailValues[i].instituteCode;
var iped:String=_xmlResult.InstituteDetails.InstituteDetailValues[i].ipedCode;
dataGridDataProvider.addItem(new InstituteLookupGrid(insti,icode,iped));
}
dgTransactions.dataProvider=dataGridDataProvider;
} */
]]>
</mx:Script>
<mx:WebService id="userRequest" showBusyCursor="true" wsdl="http://kavin-pc:8080/InstiServ/services/INSTITUTIONWSDLFile?wsdl">
<mx:operation name="INSTITUTIONQueryService" resultFormat="xml" result="getValue(event);" fault="mx.controls.Alert.show(event.fault.faultString)"/>
</mx:WebService>


<mx:VBox width="100%">


<mx:Text width="100%" text="Select Institute" fontWeight="bold"/>
<mx:Form width="100%" paddingLeft="0" paddingBottom="0" paddingRight="0" paddingTop="0">

<mx:FormItem width="100%" direction="vertical" label="Institution">
<mx:TextInput id="txtInstitution" maxChars="45">
</mx:TextInput>
</mx:FormItem>

<mx:FormItem>
<mx:Button label="Find" id="Find" click="clickHandler()"/>
</mx:FormItem>

</mx:Form>
<mx:ControlBar width="100%">
<mx:DataGrid id="dgTransactions" width="100%"
height="100%" x="0" dataProvider="{_xmlResult.INSTITUTIONQueryServiceData}">
<mx:columns>
<mx:DataGridColumn dataField="InstitutionName" headerText="Institue" width="90" headerWordWrap="true" wordWrap="true"/>
<mx:DataGridColumn dataField="InstitutionErpCode" headerText="Internal Code" color="#000000" width="90" headerWordWrap="true" wordWrap="true"/>
<mx:DataGridColumn dataField="IpedsCode" headerText="IPED Code" color="#000000" width="90" headerWordWrap="true" wordWrap="true"/>

</mx:columns>
</mx:DataGrid>
</mx:ControlBar>
<mx:HBox>
<mx:Button label="Submit" id="submitbutton" click="UpdateData()"/>
<mx:Button label="Close" click="close()"/>
</mx:HBox>

</mx:VBox>
</mx:Panel>

Where would the values be coming from?