Code issue with set salesgroup on opportunity

I'm having problem with salesteam on opportunity.  I'm setting the salesgroup value on opportunity and when I do a getvalue on the salesgroup it shows the correct value.  However when I try to access the salesteam of the opportunity, it brings up a different sales group.  Below is the code snippet.  Please advice.  Doesn't setting salesgroup automatically update salesteam on opprtunity?

nlapiSetFieldValue('custbody_sales_region', SlsRegn);
nlapiSetFieldValue('custbody_sales_territory', slstrty);
nlapiSetFieldValue('custbody_department', SlsDept);
nlapiSetFieldText('salesgroup', SlsTeam);


var salesteam = nlapiGetFieldText('salesgroup');
nlapiLogExecution('DEBUG', 'salesteam', salesteam);
var salesteam1 = nlapiGetFieldValue('salesteam');
nlapiLogExecution('DEBUG', 'salesteam1', salesteam1);

var nbSalesTeam = nlapiGetLineItemCount("salesteam");
nlapiLogExecution('DEBUG', 'nbSalesTeam', nbSalesTeam);