Code for add &update ListItem in sharepoint2010

Code for Adding ListItem:

try
{
SPWeb certusweb = SPContext.Current.Web;
SPList lstName = certusweb.Lists["ListName"];
SPListItem lstItem = lstName.Items.Add();
lstItem["Title"] = "Score";
lstItem["Minimum"] = txtMinimumT1.Text;
lstItem["Maximum"] = txtMaximumT1.Text;
certusweb.AllowUnsafeUpdates = true;
TierItem1.Update();
certusweb.AllowUnsafeUpdates = false;
}
catch(Exception ex)
{

Response.Writte(ex.ToString());
}


Code for Updating ListItem:


try
{
SPUser user = web.CurrentUser;
StudentId = user.Name;
SPWeb web=SPContext.Current.web;
SPlist lstName = web.Lists["ListName"];
SPQuery qry = new SPQuery();
qry.Query ="// Here you can write sample query for getting items from list " + StudentId + "";
SPListItemCollection coll = lstName.GetItems(qry);
if (coll.Count > 0)
{
foreach (SPListItem items in coll)
{
if (!string.IsNullOrEmpty(txtFname.Text))
items["FirstName"] = txtFname.Text;
if (!string.IsNullOrEmpty(txtLname.Text))
items["LastName"] = txtLname.Text;
if (rdbMale.Checked)
items["Sex"] = "Male";
else if (rdbFemale.Checked)
items["Sex"] = "Female";
if (!string.IsNullOrEmpty(txtState.Text))
items["State"] = txtState.Text;
web.AllowUnsafeUpdates = true;
items.Update();
web.AllowUnsafeUpdates = false;
}
}
}
catch(Exception ex)
{

Response.Writte(ex.ToString());
}