FMP lasso and if statement

[soup]

So I have 160 fields, ex. s1,s2,s3 etc. If a customer purchases 5 small items I need lasso to create 5 input text fields with the name being s1 for the first, s2 for the second etc. so when the information is placed from the client into the text field it is sent to the appropriate field in FMP. the only idea I can think of is, [if ('field:smallQua') = '1'] [/if] [if ('fieldsmallqua')=2] [/if] etc. and doing this over and over seems like there must be a way?? any clues