4. The method as claimed in claim 3 , wherein the complement characters indicate the untrusted data and the standard characters indicate the trusted data.
4. The method as claimed in claim 3 , wherein the complement characters indicate the untrusted data and the standard characters indicate the trusted data. 5. The method as claimed in claim 4 , wherein the trusted characters are contained in code on the web application and are encoded in the standard characters, and the untrusted characters are encoded in the complement characters.