Replace With HTML Ascii Codes?

I ran into a problem. Wrote the following code snippet:

teksti = teksti.Trim()
teksti = Replace(teksti, "<", "& lt;")
teksti = Replace(teksti, ">", "& gt;")
teksti = Replace(teksti, """", "& quot;")
teksti = Replace(teksti, "'", "& #8217;")

[Code]...

After writing this I realized it becomes its own problem. The function is supposed to make information safe for HTML and SQL injection (there are other methods too, parameterized queries, etc but that's beside the point). However what happens, is that it first replaces &lt; with & lt; and then proceeds to replace the newly written string again as every replace string has &, # and ; signs in it.

I thought about using a regex for this, but I couldn't find any decent Visual Basic examples that were simple enough. Edit: I was sure there would be a "smart" easy way to do this, but I guess there are no common methods available after all. The re-arranging the problem cases first is the obvious solution here,As for parametirized queries, checking back I see my English doesn't come out as intended. I meant to say that I'm already using them, that this problem here is specific to prevent all manner of html-injection and possible sql-injection using the same strings elsewhere later.