Hi
Try like this, might help you..
string s = Convert.ToString(Request["client_id"]);
string[] array = s.Split(',');
if (array.Length == 5)
{
txtFirstName.Text = array[0];
txtLastName.Text = array[1];
txtPhone.Text = array[2];
txtOthers.Text = array[3];
txtCity.Text = array[4];
}