Use With A Textbox In VB Swiping A Card With Magnetic Encoded Data?

I have created a program in Visual Basic using Microsoft Visual Studio 2010 Professional. There is a textbox that I use in the program that when the focus is placed on it will take the data encoded on a magnetic striped card such as a driver's license or any card that has this kind of data encoded magnetically. Very simple to get the data as the program takes all of it upon the swipe without having to do really anything, however, the problem is that I don't know which declaration to use when the swipe has stopped - or the last character has been entered. Currently I am using TextBox1_textChanged as my declaration, but that is called every time each character is put into the text box. When you are swiping, this is an ongoing process until the last character is put in. So if I have a magentic card with 10 characters in it, this method will be called 10 times. Is there a declaration that I can use that only fires off whent he swipe has loaded all of the characters or some kind of loop that I can incorporate?