You need to look at your websites log files and search for keywords like DECLARE or CAST or <script

You may find an entry that has an html script tag with...

You can also use the CHARINDEX function. Like so:

select ques.catid,ques.question,ques.qid,ques.subcatid,sub.subcategory from ada_question ques,ata_subcat sub where

ques.subcatid=sub.subcatid and ques.catid=1 and ques.status=1 and CHARINDEX(cast(ques.qid as varchar(50)), @qid) > 0

order by sub.subcatid,ques.qid asc