set value function gives me an error

Hi all

var contactRecords = XrmServiceToolkit.Soap.Fetch(contactFetchXML);
if (contactRecords.length > 0)
{
if (contactRecords[0].attributes.extendedamount!= undefined)
{
//alert(contactRecords[0].attributes.extendedamount.value);
//objSubGrid.control.SetParameter('fetchXml', FetchXml);
Xrm.Page.getAttribute("extendedamount").setValue('contactRecords[0].attributes.extendedamount.value') // This gives me an error which is below 
}
}

What can I do?