Loop through line items in an opportunity to find ID

Hi,

I have an opportunity and I am using some simple code to loop through the line items. My goal is to get the identifing number for each line item.

iItemCount = nlapiGetLineItemCount('item');    for ( i = 1; i <= iItemCount; i++)  {        nlapiLogExecution( 'Audit', 'internalid = ', nlapiGetLineItemValue('item', 'internalid', i));  nlapiLogExecution( 'Audit', 'amount = ', nlapiGetLineItemValue('item', 'amount', i));  nlapiLogExecution( 'Audit', 'description = ', nlapiGetLineItemValue('item', 'description', i));  }

Code works fine but i need to know the the tag is for the internal id as it is not being retrieved - anyone know what the proper tag is? internalid is not working

Thanks