TextBox and popup Grid (other .aspx)

In .aspx page I have ASP.NET
1TextBox(txtFirst) 1 Button (btnSearch)
1 TextboxtxtLast) and a MS SQL DB (Table with the fields First Name, and Last Name)
What I want it is:
- I want to enter some text in first TextBox
-After I clicked btnSearch to jump in other .aspx with a Data Grid
-After I browse what I want, I will choose a Last Name.
-After Selection I want to put the data from the Grid in both TextBoxes
Please! Thanks.

I'm on chapter 5 of the book you have just requested but in the meantime I recommend you pay 4guys a visit and read some of the excellent tutorials on asp.net, in particular the stuff on datagrids and other server controls - http://www.4guysfromrolla.com - what you want to do is quite involved and would take some time to explain what is already well documented on the net.