can't format my decimal as currency - input string was not in correct format

[jhardman]

i have decimals coming in from a SQL Server db, and displaying them without converting them works.

response.write ("<td>"& i & "</td>")

I can add and subtract without any errors

response.write ("<td>"& i+3.5 & "</td>")
response.write ("<td>"& i+0.0 & "</td>")

and i can use that last to trim off the extra decimals, so that is nice.
I can use the toString() function without arguments

response.write ("<td>"& i.ToString() & "</td>")

and this works but doesn't give me the format I want. If I try to format as currency:

response.write ("<td>"& i.ToString("C") & "</td>")

I get an error "Input string was not in a correct format". Isn't that how toString() is supposed to work? What am I doing wrong?

[Luuk]

SELECT TRY_CAST(X.A AS DECIMAL(12,2)) 
FROM (
    SELECT '2.345' as A
    UNION ALL
    SELECT '2,345'
    ) AS X
 

Use TRY_CAST in SQL server, so you KNOW that the numbers are in a correct format. (NULL is returned if they are not in a correct format)