Setup and deployment

Here is my code
pls check it!!!!!!

public static string Getid(string id)
{
SqlCommand cmd = new SqlCommand("select Id from cities where Id='" + id+"'", con);
SqlDataReader Dr;
con.Open();
Dr = cmd.ExecuteReader();
if (Dr.Read())
{
con.Close();
return "true";
}
else
{
con.Close();
return "false";
}
}
[System.Security.Permissions.SecurityPermission(System.Security.Permissions.SecurityAction.Demand)]
public override void Rollback(IDictionary savedState)
{
base.Rollback(savedState);
}
[System.Security.Permissions.SecurityPermission(System.Security.Permissions.SecurityAction.Demand)]
public override void Install(IDictionary stateSaver)
{
base.Install(stateSaver);
if(Context.Parameters["userpass"].Length>0 )
{
string data=Context.Parameters["userpass"];
string val= Getid(data);
if (val == "false")
{
stateSaver.Add("userpass", data);
base.Uninstall(stateSaver);
}

}
}
[System.Security.Permissions.SecurityPermission(System.Security.Permissions.SecurityAction.Demand)]
public override void Commit(IDictionary savedState)
{
base.Commit(savedState);
}
[System.Security.Permissions.SecurityPermission(System.Security.Permissions.SecurityAction.Demand)]
public override void Uninstall(IDictionary savedState)
{
base.Uninstall(savedState);
}