VS 2008 Handling Strings?

I once again feel so angry about VB .NET . Here's what ruined my day :Lets say we have have a string variable :

Dim Var1 As String = "blablabla"
If we want to replace something within it , we can use the Replace function :
Dim Var2 As String = Replace(Var1,"a","o")

This works great . My problem appears when I want to replace the " character (double quote) . Thus , when using :Dim Var2 As String = Replace(Var1,"""","o")it will return an error .Of course you may wonder why I care to replace the " character . You see this string variable receives its value from a text box . Thus , if the user uses the " character , I want to replace it with two ' characters (single quote) . Is this replacement possible in .NET