C # filter HTML code

// Filter HTMLCode
Public   String Checkstr ( String Html)
{
System. Text. regularexpressions. RegEx regex1 =   New System. Text. regularexpressions. RegEx ( @" <SCRIPT [\ s] + </script *> " , System. Text. regularexpressions. regexoptions. ignorecase );
System. Text. regularexpressions. RegEx regex2 =   New System. Text. regularexpressions. RegEx ( @" Href * = * [\ s] * script *: " , System. Text. regularexpressions. regexoptions. ignorecase );
System. Text. regularexpressions. RegEx regex3 =   New System. Text. regularexpressions. RegEx ( @" On [\ s] * = " , System. Text. regularexpressions. regexoptions. ignorecase );
System. Text. regularexpressions. RegEx regex4 =   New System. Text. regularexpressions. RegEx ( @" <IFRAME [\ s] + </iframe *> " , System. Text. regularexpressions. regexoptions. ignorecase );
System. Text. regularexpressions. RegEx regex5 =   New System. Text. regularexpressions. RegEx ( @" <Frameset [\ s] + </frameset *> " , System. Text. regularexpressions. regexoptions. ignorecase );
System. Text. regularexpressions. RegEx regex6 =   New System. Text. regularexpressions. RegEx ( @" \ ] + \> " , System. Text. regularexpressions. regexoptions. ignorecase );
System. Text. regularexpressions. RegEx regex7 =   New System. Text. regularexpressions. RegEx ( @" </P> " , System. Text. regularexpressions. regexoptions. ignorecase );
System. Text. regularexpressions. RegEx regex8 =   New System. Text. regularexpressions. RegEx ( @" <P> " , System. Text. regularexpressions. regexoptions. ignorecase );

Html = Regex1.replace (HTML, "" ); // Filter <SCRIPT> </SCRIPT> tags
Html = Regex2.replace (HTML, "" ); // Filter href = javascript: (<A>) attributes
Html = Regex3.replace (HTML, " _ Disibledevent = " ); // Filter on events of other controls
Html = Regex4.replace (HTML, "" ); // Filter IFRAME
Html = Regex5.replace (HTML, "" ); // Filter frameset
Html = Regex6.replace (HTML, "" ); // Filter frameset
Html = Regex7.replace (HTML, "" ); // Filter frameset
Html = Regex8.replace (HTML, "" ); // Filter frameset
Html = Html. Replace ( "   " , "" );
Html = Html. Replace ( " </Strong> " , "" );
Html = Html. Replace ( " <Strong> " , "" );
Return HTML;
}