How do I run Functions based on results of "If statements"?

I have two columns in my template: One to show the sum of Ship Weight for EU countries and the other to show the sum of Ship Weight for Non-EU countries.  How do I correct my syntax?  I have the following within the syntax properties of one field.
EU field: <?if:EU_ID='EU'?><?SUM((Weight_ID1)*(Quantity_Shipped_ID2))?><?end if?>
Non-EU field: <?if:EU_ID!='EU'?><?SUM((Weight_ID1)*(Quantity_Shipped_ID2))?><?end if?>

My RTF template validates, but when I try to run a PDF output, it gives me an error.  Do the if statements need to be outside the field?  Do I need to incorporate for-each or for-each-group statements instead?  If so, how?  Thanks in advance.