How to combine format number and if statement?

Question

Hi,
I'm using XDO 5.6.1 under apps.
My issue is to display a number only if it is not equal to zero.
Otherwise, i need to display it in european mask using format_number function.
I tried all the condition statements (if, choose) and they work perfectly.
<?xdofx:if MAR_SUM=0 then '' else MAR_SUM end if?>
format number works fine too.
format-number(MAR_SUM,"### ###.00", "Euro")
But i did not succeeded to combine if and format number
<?xdofx:if MAR_SUM=0 then '' else format-number(MAR_SUM,"### ###.00", "Euro") end if?>
The result is always a blank field, even MAR_SUM is not nul.
I can not use Word format number bacause it do not work with my mask.
Please help me, .
Thanks.
Pierre.

Answer 1

Thanks a lot Tim,
It helped me a lot. I'll simplify my tags using those tags.
I have another issue concerning cell highlight.
I have two loops in a table and when I insert <?if@row:position() mod 2=1 ?> <xsl:attribute name="background-color" xdofo:ctx="incontext">#DDDDDD</xsl:attribute>, in order to use cells highlight, my subtotals disappear at the end of my loop.
Could I send you a email with an example, (and how to contact you)?
Thank again for your response again.
Regards.
Pierre