what is Taxschild in the taSopHdrIvcInsert while econnecting sales transaction into GP

I am creating a taSopLineIvcTaxInsert_ItemsTaSopLineIvcTaxInsert node and assigning it to the SOPTransactionType object. Do I still need to assign the taxschid and the taxamt in the tasophdrivcInsert node? While doing a sales transaction in gp directly, just by choosing the right customer and taxdetail id (in sales tax summary entry screen) I could get the tax amount to hit the right accounts and so on .  Please advise what are the steps in creating a sales transction that has a sales tax amount to come in through econnect to GP.

Pelase help thanks