how to solve this using flag

I have 3 class.each class contains with different conditions.
class1
{
if(txtbox.text=="")
{
//error
}
}
class2
{
if(txtbox2.text=="a")
{
//error
}}
class3
{
if(txtbox3.text=="int")
{
//error
}}

i m callin these 3 class using reflection.
if one class encounter a error it should not
move to next classes.
But since i used reflection automatically
all 3 classes are visited..hw to solve this