There are various ways to convert data types in the .NET framework, but if you are coding with VB
.NET (not C#) then you can use the same functions you have used all along with VBScript
and so on.
The only difference is that whereas CINT() in VBScript only handled 16 bit numbers (and so was limited to the range -32768 to 32767), CINT() in VB
.NET handles full 32 bit number (+/- 2 billion). And CLNG() in VB
.NET handles 64 bit numbers. All the other Cxxxx functions remain the same.
So, if MonthlyCost is a string, you should be able to do
<%=2 * CCurr(MonthlyCost)%>
<%=2 * CDbl(MonthlyCost)%>