Article:
  Enhancing ASP.NET Pages with JavaScript
Subject:   Need help with popup box (lookup).
Date:   2007-09-21 01:15:43
From:   sunithashukla
Response to: Need help with popup box (lookup).

In first page source code write code in Script as
<script type="text/javascript" language="javascript">
function getId(ControlId,UserName)
{
document.getElementById(ControlId).value = UserName;
}
</script>
......
and next go to .cs of same page and write code as
protected void Page_Load(object sender, EventArgs e)
{
lnkbt.OnClientClick = "window.open('GridView.aspx?ControlId=" + txtName.ClientID + "')";
}


protected void Button1_Click(object sender, EventArgs e)
{
Response.Write("<script>alert('Hai')</script>");
}
...........
Go to next page and write below code in source code as
<script type="text/javascript" language="javascript">
function getData(ControlId,UserName)
{
window.opener.getId(ControlId,UserName);
window.close();
}
</script>
................
next go to .cs of this page 2 and write code as
protected void Page_Load(object sender, EventArgs e)
{
DataTable dt = new DataTable();
dt.Columns.Add("UserId");
dt.Columns.Add("UserName");
dt.Columns.Add("Password");
dt.Columns.Add("EmailId");

dt.Rows.Add("1", "Ravi", "Ravi", "Ravi@gmail.com");
dt.Rows.Add("2", "Rama", "Rama", "Rama@gmail.com");
dt.Rows.Add("3", "Ramu", "Ramu", "Ramu@gmail.com");
dt.Rows.Add("4", "Rao", "Rao", "Rao@gmail.com");




GridView1.DataSource = dt;
GridView1.DataBind();
}


protected void GridView1_RowDataBound(object sender, GridViewRowEventArgs e)
{
LinkButton lnkSelect = (LinkButton)e.Row.FindControl("lnkselect");
if (e.Row.RowType == DataControlRowType.DataRow)
{
lnkSelect.OnClientClick = "getData('" + Request.QueryString["ControlId"].ToString() + "','" + e.Row.Cells[1].Text + "');";
//lnkSelect.OnClientClick = "test();";
}
}
}
..................
Actually in this senario when we run the program and click on a button it will redirect to other page with in the window ie a popup box.In this window if we click on any row of gridview column then this window 2 will close and id will display in page 1 at textbox.
I think so this is correct answer .