Hi all.
How can i get ID of an Exception?

Depends on how you are attempting to handle the exception.

If you are using a "try catch" block, then you will need to use the exception object's number &/or message properties. For example:

Try
     ...some code...

catch e as exception
     ...code to gracefully handle exception..
     lblMessages.text = "The following error occurred: '" & e.message & "'.<br>Error Code: '" & e.number & "'.
end try

Just be sure that if you do something like this that there is a label name "lblMessages.text" in your .aspx page. ;)

I know the above uses both the .number & .message properties, but you get the idea.

What are going to do with The ID

i want my appliction to do different works with different excapetion IDs. it means action of my application after occuring an exception is dependent to number of the exception...
anyway i hope the way that pbranumfl offered work.
i am going to test it.
thanks for your replies.