Function Not Called - Problem Question Part 2

This is Part 2 to this question
http://forums.asp.net/t/1838844.aspx/1?C+Variable+not+assigned+Problem+Question+Part+1
but it can be answered by itself
I have a gridview that selects an invoice and displays it so parts can be edited.
Part of this invoice is populated by a SqlDataReader, but when I update or change part of the invoice and get a postback, the data read by the DataReader does not update even though I call the function at the end of my events and on postback, shouldn't it do a freash read and display of the data everytime I call the function?
I added a special section that clears all the labels to see if it calls the Read_Invoice_Infor() function and all I get are empty labels
// READ ITEMS THAT CANNOT BE EDITED OR DELETED ON THIS FORM private void Read_Invoice_Info() { SqlConnection vSqlCon = new SqlConnection(Config.ConString); vSqlCon.Open(); SqlCommand mpSqlCom = new SqlCommand("SELE ...