using SPSecurity.RunWithElevatedPrivileges gets an error - sharepoint

Question

the error i get is
The security validation for this page is invalid. Click Back in your Web browser, refresh the page and try the operation again.
i am using moss 2007
protected void btnSubmit_Click(Object sender, EventArgs e)
{
try
{
SPSecurity.RunWithElevatedPrivileges(delegate()
{
SPUtility.ValidateFormDigest();
using (SPSite mySite = new SPSite(_sLibUrl))
{
TextBox txtFirstName = (TextBox)usercontrol.FindControl("txtFirstName");
TextBox txtLastName = (TextBox)usercontrol.FindControl("txtLastName");
TextBox txtPhone = (TextBox)usercontrol.FindControl("txtPhone");
TextBox txtEmail = (TextBox)usercontrol.FindControl("txtEmail");
TextBox txtSubject = (TextBox)usercontrol.FindControl("txtSubject");
TextBox txtContant = (TextBox)usercontrol.FindControl("txtContant");
mySite.AllowUnsafeUpdates = true;
SPListItemCollection listItems = mySite.AllWebs[WebName].Lists[_sLibName].Items;
SPListItem item = listItems.Add();
item["FirstName"] = txtFirstName.Text;
item["LastName"] = txtLastName.Text;
item["Phone"] = txtPhone.Text;
item["Email"] = txtEmail.Text;
item["Subject"] = txtSubject.Text;
item["Contant"] = txtContant.Text;
item.Update();
mySite.AllowUnsafeUpdates = false;
mySite.AllWebs[WebName].Lists[_sLibName].Update();
txtFirstName.Text = string.Empty;
txtLastName.Text = string.Empty;
txtPhone.Text = string.Empty;
txtEmail.Text = string.Empty;
txtSubject.Text = string.Empty;
txtContant.Text = string.Empty;
}
Label lblMessage = (Label)usercontrol.FindControl("lblMessage");
// lblMessage.Text = "טופס נשלח בהצלחה";
});
}
catch (Exception ex)
{
Label lbl = (Label)usercontrol.FindControl("lblMessage");
lbl.Text = ex.Message;
}
}

Answer 1

Try putting mySite.AllowUnsafeUpdates = false; after mySite.AllWebs[WebName].Lists[_sLibName].Update();

Answer 2

i found the solution what i need to do is to remove the
mySite.AllowUnsafeUpdates = true;
and
mySite.AllowUnsafeUpdates = false;
and it works

Answer 3

I work with this solution always
using (var site = new SPSite(SPContext.Current.Site.ID))
using (var web = site.OpenWeb())
{
web.AllowUnsafeUpdates = true;
//add, update and etc. programatically crud operations with lists
web.AllowUnsafeUpdates = false;
}