Blacklist the XSS characters

Hi,

In my site i wanted to blacklist the XSS characte3rs '<' '>' etc.

For this i am using REgularExpressionValidator.
I can use the whitelisting approach... by setting the
ValidationExpression = @"^[a-zA-Z0-9#$!@^&%. ,\+_\-[\]\(\)\*\`\;\:]+$".

But i am forced to use the black listing because i have to support unicode characters in mu controls.

Can anybody suggest me what could be the ValidationExpression.
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