Input filter prevents a user from entering invalid characters into a text box. Note that since this effect can be avoided by deactivating JavaScript, you should use this extender as a convenience for your users, but you must never expect that the data being sent to the server consists of "valid" chars only.

Textbox offers a set of filter methods below:

• NumericOnly() - Only allows input Integer value.
• NumericOnly(int decimalDigits) - Only allows input numeric decimal value.
• LowerCaseOnly() - Only allows input charaters in lower case.
• UpperCaseOnly() - Only allows input charaters in upper case.
• ValidCharsOnly(string validCharaters) - Only allows valid charaters.
• InvalidChars(string invalidCharaters) - Could not allows specified valid charaters.
• InputFilter(Action filters) - Customize input filters.